You don't! there are hundreds of tiny creatures living on them, if you clean it you risk killing them, or flushes them off the moss, just leave them be, if there is stuff collecting on them, just give them a shake.
You don't! there are hundreds of tiny creatures living on them, if you clean it you risk killing them, or flushes them off the moss, just leave them be, if there is stuff collecting on them, just give them a shake.