I've known about no-shampoo, especially since it seems with my oily, dandruffy hair I need to shampoo everyday. My daughter is almost 5 and I have never put shampoo into her hair. When she bathes, I will rinse her hair in the bathwater. Her hair is fine/thin. I rinse her hair with bathwater when it gets dirty or whenever she wants to bathe (sometimes everyday or sometimes as little as once a week). While frequency ranges, her hair looks and feels great.
I have told friends to try the no-shampoo, given that shampoo is not regulated and has ingredients that are often not substantiated or checked to do what brands claim they do. One friend tried it while on vacation for two weeks at an off-the-grid bed and breakfast place in Latin America. By the time she came back she was "off" of her addiction to shampoo. I have another friend who did it as well. Her hair looked amazing, like she was always just walking out of a salon (yet, she didn't blowdry or anything, and I know since she and I were sharing hotel rooms)! She travels with a baking soda paste and a bit of apple cider vinegar for her hair but otherwise her hair seemed so low-maintenance.
I started my own no-shampoo about two weeks ago since I mostly tele-commuting. After 5 days I had to shampoo. I was happy about lasting that long. I'm back to trying this week and I am counting at 8 days. I'm rinsing everyday, giving myself a scratchy scalp rub under water, and airdry. I don't need any product. Hopefully I can last about a month to reset my hair and have hair that is no-maintenance. These last couple days have been really oily, so I have been putting up my hair in ponytails and clips. Wish me luck!