Shampoos have detergent agents in them, like sulfates and parabens. When you wash your hair every single day with shampoo, it's cleans very well the scalp but it also makes all the sebum wash away and your scalp is dry and have no means of natural moisturizer and the sebaceous glands start overproducing sebum to compensate for what the chemicals in the shampoo do to your dry head, that's where people get the oily scalp and some very oily ones.
You can stop it only if you stop washing your hair daily with shampoo and after a year or so, when your glands return to normal and your heads skin returns to normal also and after you can start to wash it only 2 times a week at maximum with shampoo. The rest you should do it only with water, and keep in mind that you should never wash it with boiled or very hot water, somewhere in between warm and cold.
All of this besides the fact that Keto should not be used more than 2 times a week, it's very harsh and dries the scalp and the hair very bad, if you use it the wrong way, it could actually cause the opposite effect of what people use it for, and that is hairloss.
