Hey, I am in the process of building my own terrarium, and I used just any wood finish, organic would be better *DONT USE LINSEED OIL* toxic to animals!. I'm sure if you sealed it without any stain, you could use vegetable oil. And not have to worry about leaving the cage to aerate over the weekend or whatever. But for mine I used the polycrilic sealant. It should work fine, I read online it wa okay as long as the fumes have been completely extinguished with time.