When I first started CGing, I couldn't imagine that water washing was something I'd ever do. Any time I'd tried just rinsing my hair out, it had ended up greasy, and it wasn't until I'd been CG for about a year that I tried water washing, using Lorraine Massey's method, which doesn't use a brush, but is based on giving the scalp a really good massage under running, hot water, then following with a rinse out conditioner, etc.
I was really shocked to find that using the CG water wash method my hair and scalp look, feel, and smell clean, not the least bit greasy, and I have great root lift, and very nice curl.
As far back as I can remember thinking about it, I've been under the impression that sebum would naturally be the best conditioner hair could have. After all, if it weren't, that would be a major design flaw, and our ancient (and near) ancestors wouldn't have been able to grow hair (and we know that's not true). So, on rare occasions, when my hair condition had deteriorated badly, I would sometimes let my hair get oily, just so it could recover -- blecky, but it worked.
Other stuff in conditioners, as we now know, can damage hair; among them mineral oil, petroleum jelly, and silicones.
Baby Fine 3B, low porosity, normal density and elasticity
CGing since July 2008