Yes. They like to dry quickly, so mounting is a good option. Remember, even mounted they can rot if they don't have enough air circulation and light. But given those things, they are tough critters.
Lots and lots of vendors use it under the roots. I hate that, because then the orchid can't get a really good grip on the mount. I always tie a little moss on top of the roots and then remove it after the orchid is established on its mount.
Thank you orchid boy! I have seen it lots of ways but wasn't sure about Enc. I know they kind of like to dry out so will use just a little of it ...Jean