I started with a bag of Cyprus mulch from a pet store, but when I got home and opened it I noticed several small (I mean, TINY) ants and even smaller white wood mites in it. I tossed the whole bag in my backyard in the middle of winter and never touched it again.

The second bag of Cyprus mulch I got was clean (from a different pet store), and I made sure to bake it at 350 for about 45 minutes. When I opened the oven door a cloud of steam hit me in the face and fogged up my glasses! However, the wood was still quite damp and took the moisture I squirted it with to regain any that was lost by baking.

When I needed new substrate the store was sold out of Cyprus, so I bought a bag of Exo Terra Jungle Carpet. I actually like it even more than the Cyprus. It holds moisture very well, and is (from what I've read) even more resistant to mold.

I also baked the lot I planned to use at 350 for about an hour. I left it to cool prior to putting it in the viv. I cover the bottom of the tank with a layer of newspaper for easy clean-up. Just roll up the newspaper and voila! No fuss, no muss.

The Exo Terra Jungle Carpet also expelled a quantity of steam after being baked, but it retained more moisture than you'd think and it also took well to moisture that was introduced through squirting with water later on.

I've had no problems with it, and my BP seems to enjoy it!

Just for fun (and pampering sake) I use some finely shreded aspen inside the hides for him to curl up in.

I've also taken to mixing a little bit of Exo Terra coco fiber husk (bought in brick form) with the substrate to better hold moisture.

My home is quite dry in the winter, usually in the 30s%, but with this setup I've been able to keep my glass viv at 50-60 without issue. I generally moisten once in the morning and once at night, allowing for drops in humidity throughout the day and night before re-misting. This is important because it simulates natural variations in climate conditions and is better for their lungs, so I've read. Makes sense to me. Too much humidity can be just as bad as not enough.

I cover about 25% of the top screen with aluminium foil (shiny side down) and a towel over it to trap heat and humidity.

I hope this helps.

PS: Baking was no issue for me. No mess, I mean. I put a few large scoops of the substrate in a deep casserole dish and that was all. For speeds sake I used two casserole dishes to get twice the substrate, although I think I only used about half of what I prepared in my 20g Kritter Keeper glass tank.