There are several ways to clean your hair without shampoo, and using any one of those methods will make it so over time, you can begin to wash your hair only with water about every 5-7 days. Look up
nopoomethod.com it explains everything and helps you determine hair type for what would work best for you. The transition period is like 6 weeks and you will look like a rat in the meantime, but over time it makes your hair stronger, shinier, not prone to grease or shedding.