Coconut husk is a sustainable orchid media. Good for tropical countries because it's easily available and retains water. The only bad thing is fungi also thrive in damp coconut husk. But treatment prior to planting and water as needed can take care the fungi problem.
I saw people grow orchid in empty coconut shell and it looks good aesthetically. I also start substituting tree fern with charcoal made of coconut shell and coconut husk mixture. More sustainable and readily available.
A lot of people using tree fern for anthurium and orchid potting media in here. Such increased demands will make people go to the forest and hack forest tree ferns.... so no more tree ferns for me.
+1 to mother earth with coconut