I was CO (conditioner only) for about two years and my hair was happier then than it ever was or has been since. I plan on going back to CO as soon as I use up this overload of products I have amassed over the years. I think by September I'll have gotten through most of it.
Conditioner only washing is just what it sounds like. The most important thing to remember is NO SILICONES. It isn't about washing or not washing, just about what you choose to wash with. It's gentler than (most) shampoos and for curls, the gentler the better.