We personally use Hydroton and peat moss for our cultures, and it works really well for us. But I know several people that like the charcoal. As for the moss, we don't use any in our cultures, and I don't know of anyone that does.
It is hardwood charcoal without lighter fluid, it is now available at alot of grocery stores, and orchid charcoal from Home Depot is the same stuff. I use peat moss, and charcoal for my springtails, no sphagnum.