The heat is what sets the paint up. I was watching one of the car shows and they went through the Dupli-Color process which included a baking period to set up the ceramic paint. If you don't bake it you'll have issues with the paint remaining soft and lifting later.
As far as using the home oven goes I was told that the process has a lot of off gassing, that the gas is toxic and that you should have a very well ventilated area. Also as one can imagine if you going to use a home oven it should be electric to prevent issues with an open flame and the gases. I'm pretty sure using the oven you're cooking your food in is not a good idea.