Don't use napisan etc as some of the pads have a PUL layer.
I thought exactly the same as Ive had 2 go hay wire on me and leak. I put up a question about it in another forum place and spoke to obsi who said that washing in nappy san wouldnt matter as you dont do that with cloth nappies due to build up ext. It apparently doesnt effect the PUL..I'll have to find it now

Ive got Obsi pads...they are fantastic and she's so helpful.