Haven't done that yet. Somone else?

Actual it's diapers, but you probably mean nappy. But that's not possible. You have to take linen. You can achive good results with them. But I'm not sure if you can use them for mash filtration. You might need hammered grist as well. The linen are very good for end filtration, getting the yeast out of the maturatued beer.

Heared about the linen filtration some years ago. A friend of mine used them to filter beer. It worked out pretty good.