This page http://motowngirl.com/content/Hair-Articles-Info/No-Shampoo-Routine.html
lists it as a best choice for an alternative, there are a couple of mentions in the comments at http://www.instructables.com/id/How-to-Go-No-Poo/
and so on. As it is an old Arab tradition, I would guess it's fairly healthy because in older times people seemed to take more care of their bodies and learned from their environment, whereas these days people watch TV ads, believe them, buy stuff in brightly coloured packaging and poison themselves. As far as the West is concerned, anyway.