I'm FNL, scraping SL, and I just... wash it. I rarely use shampoo so the below describes how I co-wash.
I keep my hair stretched at least 98% of the time, so it typically remains semi-stretched during the wash. I start by saturating my hair with conditioner, then I fully detangle my hair. Sometimes I'll even back comb it so that when I put my head over the sink to rinse the conditioner out, I can keep manipulation, (and tangles) at bay. I normally dry my hair in bantu knots.