You can bake the hardware store cypress if you are only bedding for a handful of snakes (otherwise it's too much of a hassle) for 15-20 minutes at 250 degrees. I hear freezing for 24 hours also kills bugs (if you have a deep freeze you could just drop a big bag in for a day or two?) but I would trust baking it more. I believe most bugs found in cypress mulch are completely harmless, however. There is some research out there on it already, I just haven't the time to dig it up right now. Good luck!