Question about a Particle Board Enclosure

[Corn_Owner]

So I just bought two particle board enclosures. The kind of board with like a laminate covering. They are approx. 1-1/2' H x 4' L x 2' W. Both have glass framed fronts. One of them has some kind of heating pad (almost looks like a solar panel) on the inside bottom. The other does not have any kind of heating element. Looks like it was taken out. They have been sitting outside for a couple days. The previous owners used them for a couple years for snakes.

My question is what should I use to clean the inside of them? And what type of heating element should I use?

I currently have a baby red tail in a 20gal glass tank, a snow corn (almost 4ft long) in a 40gal glass tank and a creamsicle corn (about 3ft long) in a 20 gal glass tank. All use the UTH and I also use a Repti Fogger in all three as I live in Colorado Springs and the humidity here is very low.

I want to get them cleaned out and set up to proper warm side levels before moving them into these enclosures. I'm going to put my corns in them. Once my red tail outgrows his 20gal tank I will move him into one and the smaller corn will go into the 40gal.

Any suggestions/guidance will be appreciated. Thanks.