An interesting discussion came up on Nature's Nexus forum. There was a lot of valuable input from members. It started with the idea that soap is the best thing for your hair. But there were problems using soap as it proved hard to rinse out if hard water is used. Rain water is suggested to help with rinsing.

Then a member, Helen, of Zen Soaps who has done extensive research into the subject and has in the past formulated a dog shampoo added her thoughts and basically her experience put everybody straight.