made with air dry and oven bake clay. now what?

i made these little clown ghosts and the stupid mistake of using clay that dried in different conditions. i thought the black clay i got from hobby lobby would eventually give out and dry but i guess not. plus at the time the only black model magic available was ripped out of a multi pack by some asshole. i’m thinking going over it with a heat gun or hair dryer, i don’t want to damage the model magic and/or cause a fire. i went through hell and back for the tiny card symbols