Baked-on messes inside the oven can be nearly impossible to scrub away. But it doesn't make sense to reach for chemical oven cleaners, since you use your oven to bake, roast and broil dinner. Try this highly useful and nontoxic alternative instead: Make a thick paste out of dish soap, baking soda and kosher salt. Apply the paste all over the inside of the oven, and let it sit overnight. The next morning, use a wet sponge to wipe away the grimy mess naturally.