Unless it's a wool outer (eg ecobubs, which has a microfleece inner anyway), you won't get a 100% natural material pocket nappy, as it needs a waterproof outer layer. If you want 100% natural you'll need fitteds with wool covers, or AIOs / pockets with a natural inner. The most commonly used natural fibre used for inners in pockets/AIOS is cotton velour (eg: Swaddlebees), but most pockets / AIOS have stay-dry fabrics like microfleece / suedecloth.

I know that doesn't help much LOL!