with injuries like those it isn't just the cuts on the nose that are bad, but the infections and other bad stuff that can happen when they have open wounds. i would try neosporin or bedadine. with a q-tip, but i'm not a vet so don't quote me. as far as substrate, moss isn't any cleaner than anything else, it's probably messier. moss would def. coushin her fall though and WD seem to like moist (not wet) moss.