Women's nylons that are cut about as high as the start of the theoretical calf seem to be the best way to filter and knead my Kava. They seem to last a long time (relatively), are fairly fine compared to other cloths, don't clog, are already in the right shape (you just have to cut a perpendicular slit to make two 'strands' to tie) and are easily cleaned and re-used. I have made Kava in my car using just the root, a small bowl and a women's nylon. Don't know if that will work for you, but you could always prepare the Kava then keep it in a bottle for later.