You can make a humid hide out of a plastic food-storage container that has a lid, just get a container that is appropriately sized for your snakes. Cut an access hole or a corner off the lid so the snake can climb into it, fill the container with the damp moss or cocoa husk, and replace your cool side hide with it. I had great luck with it for my young BRB when his humidity had to be 80% or higher.

The only downside is that the snake tends to use it as a toilet, so you go through a lot of cocoa husk/moss compared to paper towels. On the flip side, it makes the tub easy to clean because all the mess is contained in the humid hide. I made several so when one was dirty I just swapped it out with a clean one.