If you use your own bark, that should be fine as long as you soak it in a bucket with something to kill bugs and to disinfect, for about 24 hours. To me, using what is at hand is a good idea. And in addition to some of the moss, i'd add some little rocks as well. Not many...maybe a couple medium sized rocks at the bottom of the pot for an airwell. Again, however, your ingrediants will still need to be cleaned up.