If you don't want to use harsh cleansers on your oven you can make a simple mixture of white vinegar and baking soda that can do the job. Lightly moisten the interior of your oven with water and then apply a thick layer of baking soda. Allow the baking soda to sit for about three hours and then spray the entire oven with white vinegar in a spray bottle. You will notice that when the vinegar hits the baking soda, fizzing occurs. This fizzing action helps remove stuck-on mess almost as easily as any commercial cleaner. Allow the vinegar and baking soda to sit for a few more hours and then, simply remove with a damp sponge and some water.