I use Soap Nuts with a few drops of essential oil. So far so good, though I have resorted to spray when I've had a stain...the only reason I get a stain is when I forget to wash, so it shouldn't be a problem for non-lazy people.

Celsie, I find any smell goes away after a bit of time outside? My line's undercover though, so I have the luxury of doing that, I just leave it for a day or so. Perhaps the essential oil in the wash helps too. And not leaving nappies too long before washing...that makes them stink. Maybe vinegar could help strip any residue that's causing a smell?