No Shampoo
You don't need shampoo. I have not used in 3+ years save for once in a year or so when someone, grandmother, let's say, wanted to wash me, and I did not know how to say "I refuse" without being mean... I think it's great if you try and answer honestly why you're not doing it, or if someone you know won't care is asking, just don't tell them, and don't let them control you, and don't try to please them (a form of self-defeating control). You have the right to be yourself. Not being so will simply cause bitterness, or at least a giving up on everyone being happy, choosing only you or others.
There is infinite abundance in this Universe, infinite love, so both get happiness in reality.