Here's my answer to a similar topic.

We use an inch layer of Coconut Fiber and over that a layer of Cypress. After a couple of different trial and error runs for our snakes we settled on this formula. We did a 50/50 mix of the two and it really wasn't much different than straight up Coconut. Layering the substrate seems to allow for a slower release/burn off of the humidity in the Coconut. Plus we have one snake that spends large amounts of time "playing", for lack of a better word, in the Cypress. We do not feed them in their enclosures, rather we have several Sterilite tubs that we use for feeding. Though all of our snakes are snakes that we handle regularly and are used to being moved and touched. They also now know when they are set in the tub that it is time to feed, which is interesting to watch their behavior change. Anway, I know I am a relative newb, but we have been experimenting with substrates now since we got our first snake, trying to come up with the ideal one mostly due to Arizona's complete lack of humidity. The layered system works best so far.

Regards,
Paul