Hair Science: How well do mild cleansers really clean hair?

This is a bit of a compilation piece. I have done some of these before and some for BGLH but finally I am putting all of them together right here!

The Experiment

I used my own shed hair (natural, African , 4c if you are into hair typing) and imaged it:
-on its own without any washing
- washed with shampoo only (2 minute water rinse, 2 minute shampoo wash, 2 minute water rinse and air dried for 4 hours)
-washed with cleanser only ( 2 minute water rinse, 2 minute cleanser), 2 minute water rinse and air dried for 4 hours)
-cleansers with extra time 10 minutes instead of 2 minutes - ACV, baking soda shikakai

Quick Cleansing Results

Ability of Hair Cleansers to Remove Oil  from Hair

Best Cleansers (Complete visible oil removal) Good Cleansers (vast majority of oil removed) Worst Cleansers (little to no oil removal)
Shampoo Hair Conditioner Baking soda
Oat water Castile soap (diluted) Shikakai
Natural soap/shampoo bar Bentonite Clay Apple Cider Vinegar

Rhassoul Clay

The Results

1. The Controls - Oily Hair (Dirty/Oily Reference) and Shampooed Hair (Clean Reference)

The controls let you have a baseline of what the hair looks like prior to washing and what it looks like with a proper wash. You can therefore judge the clay washes in context of dirty and clean hair.

Oily natural hair

Clean shampooed natural hair

2. Hair conditioner only - Result: Mostly Clean Hair

Co washing or washing hair with hair conditioner only does remove the vast majority of surface oil. Some small oil deposits are visible after a 2 minute cleanse as circled in white.

3. Oat water- Result: Clean Hair

I recently theorised that oat water may be able to cleanse hair due to saponins released when they are boiled. This experiment showed that indeed the cleansing with oat water does work (Process - 1 tablespoon of oats to half cup of hot water. Oats boiled for approximately 2 minutes in water, allowed to cool and then oats sifted from water. Water is then used to cleanse hair.)

4. Castile soap - Result Mostly Clean Hair

In this experiment castile soap was diluted 1:5 with water. It resulted in mostly clean hair with some oil deposits left (circled in red). Using undiluted or less diluted castile soap may result in complete oil layer removal.

5. Natural soap - shampoo bar - Result: Clean Hair

I used traditional soap (olive oil mixed with sodium hydroxide to make soap) and the result was clean hair comparable to shampoo. I would, however, just mention that soap may not be a mild cleanser as some people are more sensitive to its alkaline (high) pH. The same applies for castile soap above.

6. Baking soda - Result: Hair still oily

Many naturals tout baking soda as a natural cleanser but in my experiment, it really did not cleanse at all. The hair was extremely oily even after a 10 minute soak and rub.

7. Bentonite clay - Result: Mostly Clean Hair

Bentonite clay produced a similar result to conditioner washed hair. Hair was mostly clean with a few oil deposits (circled in white) left behind. The clay was applied to hair as a mask (water and bentonite clay mixed to a paste).

8. Rhassoul clay - Result: Mostly Clean Hair

 Rhassoul clay equally produced a similar result to bentonite clay. Hair was mostly clean with some few deposits of oil

9. Shikakai- Result: Hair still oily

Shikakai is promoted as an ayurvedic cleanser. It is made from crushed acacia pods which contain saponins which are natural cleansers. In this experiment though, the shikakai paste did not cleanse hair well. Large deposits of oil were still present on hair.

10. Apple cider vinegar- Result: Hair still oily

Some naturals do promote apple cider vinegar as a natural cleanser. It did however produce the worst result of all the cleansers. The hair actually looked oilier than when it started despite prolonging the cleansing time. It did not cleanse the hair at all in this experiment.

Additional Notes
Hair conditioner - L'oreal Eversleek Smoothing Conditioner, Shampoo - Johnson and Johnson baby shampoo, Oats - Quaker Oats, Baking Soda - Sainsbury's, Shikakai - Hesh, Apple Cider Vinegar - Sainsbury's, Bentonite and Rhassoul Clay - Sheabutter Cottage, Castile soap - Dr. Bronners, Natural Soap - Mother in Law made it.

Please do note that under the microscope we can see oil layers but we do not see small deposits on hair e.g hair conditioner deposits (well you actually could see them with specialised instruments but not with my microscope!). Strictly speaking this experiment will answer the question, how well will washing method X remove oil from hair.


  1. Well done on the experiment, and that for sharing your knowledge with us. So my question is this.

    Does ACV really get rid of scalp build up and lay cuticles flat, as they say.

    1. I would say no to the scalp build up and yes to smoothing cuticles after hair has been cleansed with shampoo or soap. It is an acid so it would be able to smooth cuticles due to the lower pH

  2. You should have tried the combo baking soda + apple vinegar (or any other vinegar for that matter) as the baking soda is a base and the vinegar acidic, so when you pour the vinegar on baking soda it will foam.
    I tried it once on my hair and it seemed clean, but of course I didn't take any extreme close ups.

    1. I will have to look up the chemistry on that to see what is happening during the reaction of the baking soda with acid!

  3. This was interesting. Because I rarely use oil on my hair, I am wondering if you used oil directly or if the buildup was due to products containing oil? Incidentally, I know someone who swears by ACV rinses and your results were less than promising. Have you ever tried Soap Nut/Berry shampoo? Feels cleansing to me :)

  4. Hi Jc,
    This is an interesting experiment. I've tried some of these cleansers from each of your ratings, but shampoo works best for me. Thanks for doing this experiment and sharing your results.

    Take care,

  5. The baking soda experiment is very interresting. Could it mean that people who experience dryness and breakage with it, in fact suffer from the consequence of the amount of build up?

    sorry for my English, I'm not a nativespeaker :-)


  6. Yay, JC, new blog posts =) Fascinating that oat water should make such a good cleanser. With it being, presumably, of a really low thickness / viscosity, how do you actually use it on the hair? Does it not just run straight off the hair strands into the bath?

    Might try this on my medium texture, prone to frizz straight Caucasian hair and see if my results are as favourable as yours. It'd be amazing (super cheap, and very environmentally sustainable) if we could all ditch the store bought shampoos in favour of oats!

    I read somewhere that the shampoos prime the hair ready for conditioner - both being of opposite charge? I wonder whether conditioner would adsorb to the hair as well if only using oat water?

    So much excitement for these experiments! <3


  7. JC,

    In regards to bentonite clay after using it as a mask and rinsing out, I immediately noticed it loosened my texture but only the strands that have heat damage. Do you know why that is? Thanks!


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