If you have to use shampoo on your curls, the #1 rule is to dilute it.
People use store-bought shampoo straight out of the bottle for a number of reasons. And sometimes you just HAVE to get that product buildup off, especially if you test/review products.
I once heard a natural hair stylist say that she never uses full strength shampoo directly out of the bottle on naturally curly hair. She always dilutes shampoo with water. I’m not sure what the ratio is, but it makes senses.
Diluted shampoo still works, so don’t worry about that. It just won’t be as harsh on your hair as a regular shampoo would be.
I only use regular shampoo when I want to clarify (get a a certain amount of product/dirt/gunk off). Any other time, I use a conditioner to help keep my curls buildup-free.
When I have to clean my hair to the extent where I have to get buildup off, most times I make my own with liquid castile soap and tea(s). Its mostly simple!
All you need is your favorite herb (Nettle, Horsetail, Hibiscus, etc), or your favorite tea (Green tea, Red Tea, White tea, Black tea). Use that instead of plain water to dilute liquid castile soap.