I just rinse with hot water and wash with the nappies and towels - I don't soak 'cause I wash then with MCNs. I use 2 or 3 per poo so I guess it depends on how many poos a day and how often you wash as to how many to get. I use a cut up flannelette nappies, but I understand that other fabrics are better (i'm just too lazy to go to Spotlight to get it, and I had the flannelette nappies not being used)