I've vermi-composted old tee-shirts, they were 100% cotton. It took my worms a couple of months to make them completely disappear. I have also used polyester which I didn't want to be eaten and it's been over 18 months and the polyester fabric is still intact. I use it as a filter to allow water to drain but keep the worms inside their towers. I find raising worms so relaxing and my plants loves the castings. I also love the fact that there is no waste of food scraps, egg shells, shredded paper, card board, dry leaves and dry grass, banana peels, citrus rinds, coffee grounds and filters etc.. Also there is no smell. It's a beautiful thing!
