I have wavy waist length hair and I currently shampoo once every 7-9 days with a non SLS shampoo and conditioner. I can't bring myself to just use water. 5 days after washing I will refresh the roots of my hair and get rid of product build up by distributing water in just the roots, by morning the roots are fairly waxy, which I like because they make styling so much easier and my hair always looks better.
Before I switched to non SLS shampoo I couldn't go a day without washing, now I'm finding that the period I can go between washing is becoming longer, I'm still experimenting with my routine but I've been doing this for 8 months now and my hair is the nicest it's ever been, and you're saving so much time and money too.
Yes, I'm thinking that might be the way for me too. Have you ever tried plain glycerine soap?
Also wondering if its taking some time to get rid of residue from the silicone rich conditioner that came with my hair dye. Maybe some of the wariness is it breaking own? I don't know. My hair is really nice right now. I did wash sort of on Friday by applying a little shampoo to my dry hair in problem spots away from my scalp and then adding water.