I was just commenting on Carmen's Braiding and Banding technique when I decided to make a proper post about my own lack of b&b to explain that it isn't sheer laziness or rebellion or ignorance that led me to my decision. I figured I would take my chances because I learned to wash my hair while it was still twisted several years ago.
Truth be told back then I was just lazy (no, I'll say that I was busy. I was in school and working two part-time jobs.) I didn't have three hours to take them all down and three more to put them back in every three weeks, so one time I just washed it with them in. Nothing bad happened, so I kept doing it.
The twists didn't unravel and my hair got clean. I didn't experience extreme puffiness or frizzies. At the time I was more afraid that it would lock unintentionally, but I learned that if I combed out the tangles at the ends it wouldn't. Plus I retwisted in sections, so that they were not ever in for more than 2 months. So I figured if I my hair held up well with 2 strand twists, it should certainly be fine with my SL 4 pt pattern, and so far it has been.
This time around I have been concerned about the impact it might have on my attempts to lock, but like I said, I know how to wash it gently. I don't over-manipulate my locks. I do concentrate mostly on the scalp. I was feeling my locks today and they seem to be coming along fine. No buds yet, but a few balls. Some of them definitely feel tighter and denser in places. And I can tell that my shed hairs are beginning to tangle into the pattern; they are not coming out even when I wash. And you'll notice I said I only wash it once every three weeks.
I'm sure some people find that appalling, but I already had a rather organic approach to washing my hair. I remember reading several articles years ago that said we don't need to wash our hair several times a week, or even weekly, unless we sweat excessively or have a scalp condition. I had a stylist explain to me once that if you don't wash frequently then you allow your scalp to regulate itself when it comes to producing natural oils and staying healthy.
I've scarcely washed my hair more than once every two or three weeks for 10 years or more, and to no ill effects. (Unless I went swimming a lot or spent days sweating in the sun for some reason. Then I always washed on an as-needed basis) And I guess my scalp has self-regulated because I've never experienced itchiness or bad smells. Even when I was wearing it straightened, I washed at the same frequency. I never used gels or greasy products that built up, so washing it less often has never been an issue.