I think the size of the cage is fine for each snake, it is trying to fill it that is the hard part since you want to keep the maintenance low, anything with detail will take a little more effort to clean. You can use the same thing that they use for the bearded dragons, I believe they seal them so they resist moisture. you can also do the same thing they use for dart frog enclosures with the Great Stuff foam, silicone and coco fiber.