The paper towels usually last me a few extra hours after a misting. Though it depends how hot your temps are. When I left for school I would leave it around 80F and the humidity stayed constant longer. I haven't used sphagnum moss but I think the sphagnum alone would be pretty helpful! You should experiment when you have time! If you're worried about bacteria I heard you can bake the moss to get rid of bugs and lingering bacteria before using it.