I normally rinse my hair and scalp thoroughly with just water, working my hands around the scalp once or twice. I have a friend who uses baking soda as a shampoo substitute, but I've never felt the need to try it.

When I had hair, I just rinsed it under water. Water is already a pretty good sovent, but isn't nearly as aggressive as detergents in shampoo.

Nobody I knew realized that I didn't use shampoo. I told lots of people that I didn't use it and they were shocked that it was even possible. My hair was fine. They weren't just being nice. I also discovered that a few other people in my social circle also didn't use shampoo, including some women with longer hair. I'd have never guessed.