Deep cleaning: Myths and suggestions

One of the most popular things to read about when researching locks is the importance of deep cleaning. Many people use baking soda and apple cider vinegar to deep clean their locks, and recommend soaking locks in this mixture once a year to remove buildup. However, despite the overwhelming popularity of this recipe, I do not suggest using baking soda for soaks, for similar reasons to why I don’t suggest Castile soap. Here is a long summary of my chemical studies and viewpoints on the traditional deep clean ingredients, as well as what I do to deep clean.

Mixing ACV and baking soda does not work

Simply put, ACV and BS together cancel each other out. In chemistry, the reaction that occurs between vinegar (acetic acid, CH3COOH) and baking soda (sodium bicarbonate, NaHCO3) is called a double replacement reaction. The active ingredients evaporate as air (carbon dioxide, CO2), and what is left behind in your bowl/sink is salt water. The fizzy “volcano effect” you get when you mix them together is the evaporation action taking place. In sum, doing this is a waste of ingredients; it literally turns your ingredients into air.

ACV is not a strong cleanser

In 1994, the Journal of Environmental Health compared the cleaning power or commercial products and natural products, such as vinegar, baking soda, and lemon juice.

The experiment had two criteria for cleanliness:

  1. Bacterial reduction (more bacteria = more chance for mold)
  2. Soil reduction (surface cleanliness)

For this experiment, “soil” was a simulated mixture of what one may often find in locks. It was made of synthetic sebum, soap residue, water, and a little bit of dirt/debris.

The results for the two cleanliness metrics are a little overwhelming to outline for the purposes of this article — but Table 2b within the study summarizes the conclusions quite well.

Table 2b: Effectiveness of cleaners on simulated bathroom so¡l as evaluated by differences in group means (Tukey test alpha = 0.05)
click to toggle results
Cleaner Microbial Reduction Soil Removal
Water Least Effective High Intermediate
Alternative Cleaners
Lemon juice Intermediate High intermediate
Vinegar Most effective Least effective
Baking soda Intermediate High intermediate
Borax Least effective High intermediate
Commercial hard surface cleaners
Without disinfectant Most effective Most effective
With disinfectant Most effective Low intermediate
Essentially, vinegar kills some strains of bacteria because of its low pH. (The bacteria used in this test was particularly pH-sensitive, so the vinegar was highly effective — though this is not the case with all microbes.) But when it comes to actually removing soil, vinegar was among the least effective of all things tested.

The conclusion of the study states, “The results indicate that compared to commercial cleaners, the alternative cleaners as a group are less effective in both microbial reduction and soil removal. However, the alternatives vary in their effectiveness … Vinegar was more effective in reducing microbial contamination than the other alternative cleaners but was least effective in removing soil. All of the cleaners, including water, could conceivably have removed the soil from the tiles with enough cleaning strokes. Therefore, consumers who wish to use alternative cleaners may find them effective in removing soil if they are willing to work harder.”

In sum, vinegar and water have the same cleaning power when it comes to getting gunk out of your hair. Neither of them clean soil particularly well by merit of their chemical composition; rather, it’s the amount of mechanical abrasion (scrubbing) you put into it. Your hands are doing all the work, not the vinegar itself.

The study did show, however, that vinegar does reduce microbe count, which water does not do. So if you suspect you have a mildew problem, then vinegar soaks can help. Another thing vinegar can do is help dissolve soap scum buildup in your hair; the acid dissolves the mineral precipitate and allows it to be washed away. But aside from mildew or soap scum buildup, vinegar will not have any meaningful effect on removing dirt and oil.

Baking soda doesn’t clean well on its own

Like vinegar, baking soda does not do a great job of cleaning hair. This is for a few reasons.It is not a surfactant (soap or detergent). It is not polar. It has no value for cleaning that water does not already possess. Click here to see microscopic photos of hair “cleaned” with baking soda.

Additionally, baking soda’s pH is too high for the scalp. This can cause irritation and also lowers the scalp’s ability to fight off bacteria and mildew.

Baking soda’s properties are also a threat to the health of your hair strands. Baking soda is a mild abrasive, so when scrubbed on the head, it shreds and can even remove the cuticle layer of your hair strands. When used as a soak instead of a scrub, the high pH of baking soda raises the cuticles. The lifted cuticles make your hair rapidly lose moisture, swell excessively in the cortex, feel scratchy to the touch, and ultimately cause breakage and shedding.

Lastly, the high pH of baking soda also encourages hard water minerals to ionically bond to the hair shaft of each strand, which makes your hair even harder to keep healthy and moisturized.

ACV rinses do not undo damage

Many people recommend using baking soda first, rinsing it out, then following up with ACV to “undo” the potential damage baking soda can cause. Beyond the fact that baking soda doesn’t clean hair in the first place, vinegar cannot simply revert your hair back to its original state after being subjected to the alkaline environment of the baking soda.

Flip-flopping the pH environment of your hair makes your cuticles raise and lower. But like a rubber band or a thin sheet of metal, the cuticles can only bend/stretch so much before they become stiff, brittle, and prone to breakage. Therefore, it is ideal to avoid raising and lowering your cuticles. The ideal goal is to keep your cuticles more-or-less in the same position: lowered.

Otherwise, moving them too much results in hygral fatigue, which is a direct cause of cuticle damage. Baking soda makes your hair strands swell excessively with water, then vinegar traps that water inside of your hair, making the strand brittle and “overfilled,” like a balloon about to pop.

What works?

When you’re trying to remove grime from your hair, you want to maximize the cleaning power of every ingredient. Water is called the “universal solvent,” so it’s a great ingredient for a soak. Water doesn’t dissolves oils or other fatty, nonpolar ickies that stick to your hair. So you’ll want something that targets that as well. Any surfactant will work well for this purpose. I prefer clarifying shampoo to do this. Lastly, you want the soak to work quickly and effectively. Heat catalyzes chemical reactions (including dissolutions), so making your soak as hot as you can stand will help get the most gunk out of your hair is the shortest amount of time. In addition to making the process go faster, the heat also kills off some forms of bacteria and microbes.

Deep cleaning recipe
  1. Wash hair twice in shower with clarifying shampoo (feel free to substitute the shampoo with the surfactant of your choosing — many people prefer organic dish soap). Rinse well.
  2. Heat a pot of distilled water to the hottest temperature your scalp can safely and comfortably handle. Pour it in a bucket, add four cups of vinegar to it, sand soak locks for 15-30 minutes.
  3. Rinse well with cold water afterward to prevent rapid evaporation and stave off mildew.

I do this as needed. Compared to ACV+BS soaks (which I’ve tried several times), this method has worked far, far more effectively for me.


These are the reasons why Brambleroots discourages our clients from using baking soda on their hair. Vinegar has its uses, but not particularly for deep cleaning — unless you have mildew or buildup caused by soap scum. Ideally, “deep clean” soaks should not be needed at all if your washing regimen is sufficiently residue-free. However, it can take years of experimenting and practice to find products and habits that work for your hair, so you might need a few soaks during that time while you figure out what floats your boat.

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