Good idea!
How about getting first some Moss growing on the outside. I heard of people chopping up Moss in a blender with Buttermilk or Yogurt, painting the mixture on the surface of the pot and setting the pot into a moist shady spot.
Once the Moss starts growing, it might be much easier to get a small Orchid established. Btw some unglazed/porous terracotta wine cooler or similar have also been used for this purpose.
