I've been searching for a good liquid shampoo recipe but everything I find calls for castile soap. Is it possible to make shampoo from scratch with out using castile coap?
Do you mean making a liquid soap from scratch using KOH? Or using already made "castille" soap, grating it, and adding it to water?
If you mean the later, don't bother, it makes snot. Many many people have experimented that one to death with no successes, I don't care what the blogs say.
If you mean the former (liquid soap from scratch), go dig in the liquid soap forum here. Susie and Irish Lass have put together some spectacular tutorials.
Now, whether either is good for your hair, try it and see, but be prepared to be disappointed. That said, I like to wash my hair with salt bars and a vinegar rinse once or twice a month, so go with what works for you.