I'm no wood expert but I do know that is plywood which is composed of veneer and resins.
Baking it could be toxic because of the resins
Cheaper plywood is made with softwoods like cedar, pine and a dozen other woods.
I wouldn't use any item that can absorb urites and feces as a hide with a bottom. Sometimes they're overlooked during cleanings and the feces/urites build up causing bacterial infections.
You could seal it with polyurethane. Be careful of fumes from the sealants of course.