I have been doing this for my hair for the past 3 years. I twist or braid my hair and wear for 3-4 weeks. I may rinse in between, maybe even no-poo.
But mostly I let it go. I spray rosemary spritz almost daily, but it is low maintenance. Not for growth, but for my schedule. I work out and all, but my hair don't stink, and it's not overly dirty either.
My scalp doesn't suffer.
I am thinking of stretching my 9 yo's washings out to every 3-4 weeks. I used to do it every week. But every week, tons of hair would come out. Then I switched it to every 2 weeks. It did better. But her hair looks and stays better when I take it loose on the off week, oil her hair and scalp with my rosemary/tea tree/castor combo and rebraid. It shines a lot more. It feels stronger and it holds the style better. I don't comb it duirng the off week, I just repart, oil it, and braid a new style.
I'm thinking that if I do the loosen/rebraid/repart/oil/braid for three weeks and wash every 4th week. Especially during the winter months, when he hair suffers the most.
My youngest's (5 yo) head would not go for it. Her hair collects lint like a magnet and needs to be washed at least every 3 weeks if not every week. I think for her, I can get away with a CW every other week.
I'll let you know how it goes.
I think I will wash both of them this weekend and see what happens from there. I have anew deep conditioner that I want to try on my oldest. I believe that her hair will love it.