I wash them in 1/4 the amount of non bio (usually gel, sometimes liquid) on a 60 degree superwash (prewash, wash, rinse, spin) I hang dry all my outers and often hang dry my inserts etc now as well as I have so many nappies I dont "need" them dry quickly. I dont bother using white vinegar or anything on them, the only inserts that really get stiff are the Itti SIO and the Blueberry ones and some of the night nappies I always finnish in the drier as they are softer that way!
I dont use any nappy specific product and I dry pail. I dont have any problems with stains or smells.