I actually grow most of my Paphs in coconut husk chips (CHC) mixed with lava rock or LECA. Coconut, when watered thoroughly, retains a LOT of water, and then releases it slowly, which has been great for me, growing here in dry Colorado.
For more information about growing in CHC, the articles written by Bob Wellenstein at Antec labs are the best I've seen, with lots of raw data for those of us who like it
. You can find them here:
http://ladyslipper.com/coco3.htm
I should also mention that Hadley Cash of Marriot Orchids, the well known complex hybridizer, grows all of his Paphs in CHC mixed with LECA (and a small amount of charcoal).
- Matthew Gore