Tiger, I've thought about doing that as well, but the cresties don't cooperate especially well -- they prefer to p00 on leaves. Aside from that, I think it would essentially be similar to the forest floor, and not especially troublesome or dangerous. Fast, de Vosjoli, and Repashy are about as authoritative sources for crestie info as you'll get anytime soon, and if they feel comfortable making the option known to novice keepers, that's good enough for me. As far as the Jungle Mix, it sounds like a perfectly adequate option to their homemade mix, and if you can handle the millipedes, so much the better. (I don't think I'll ever be brave enough for that. Gators, sure, millipedes, not so much.)