I'd do either a plain hot wash, or a strip wash with bicarb & vinegar. Perhaps you've used too much washing powder? This makes nappies REEK. Stains do eventually sun out.. I don't worry too much about stains, but the smell I do try to get out.

Mum2three - LOL at the toploader. I nearly cried when we were living at mums.. she has a toploader.. and the amount of lint that came off the nappies coz it was so rough on them. It pretty much wrecked some of the nappies.. and I could never get them clean! So i sometimes had to put them through that rough washing twice! I'm much happier now I'm back with my frontloader