for stones you can bleach them or boil them on the stove, or if you are paranoid like me do both. I soak mine in a bleach water mixture for a hour or so then boil them. I don't use wood anymore because my lizards like to poo all over them, but when I did, I soaked them in a bleach and water mix then baked them in the over for 2 hours at 250 degrees like stated above. I also spray all decorations with PAM when they go in the cages.