I always grow my small Phals i 100% moss and it works better than bark for me. I usually plant them in a glass vase without any holes. Then i just pour a small amount of water in the vase and the moss distributes it itself. That way the moss just stays damp and not wet. If it gets too wet it will sink togehter and the roots starts to rot.
But then again, I grow in a climate with a quite low air humidity. :/