DS has his hair washed maybe once a week, depending on how much food/dirt/makeup he's rubbed into it. He has a bath most nights as it's part of the routine, but hairwash has always been him in the bath and the same water used. It was just warm water until his hair was actually getting dirty, now we use an organic dill and cammomile shampoo when we need it. Smells divine and promotes sleepiness.

We did wash nightly and oil DS up and got rid of cradle cap... once we stopped that it came back. So we don't shave all his hair off any more but leave him with a bit every haircut.