doesn't fleece repel moisture? so it would be soft and snuggly, but not really absorbant? i though that's why they had the bamboo/hemp inners - as the others repel the moisure back into the middle (hence why they use fleece as covers)

if it works, fantastic - i'd just be worried you're gonna make a nappy that will be a "wall" to stop liquid going any where and it will sit there making your bubba uncomfy as nothing is taking the moisture away from his butt

ETA - just read again re bamboo inners - should be fine - i use flats/fitteds with fleece/fleece or fleece/minky covers all the time and have no leakage issues