I don't treat it at all. I just make sure it is only cypress mulch, and not a blend or any dyed mulch. Some people say to bake it on cookie sheets to kill any bugs that may be in it, but I haven't had any problems using it untreated with 30+ snakes. There may be some tiny bugs in some of it, but they are not reptile mites or tick or anything like that, so seeing the occasional tiny bug won't be the end of the world. If you get a batch and notice bugs in it, or you just want to play it safe you can bake it on a cookie sheet at 250 for an hour. I also like the fact that mulch is moist and helps keep the humidity high, but if you bake it, it will dry out, so you might as well just use aspen if you are going to bake the mulch, imho.
What are these mojavas I keep hearing so much about?