Vinegar can be combined with baking soda to make an effective, inexpensive and non-toxic oven cleaner. The vinegar reacts with the baking soda to create a foam that is easy to apply to oven walls.
Let the oven cool, and remove the racks. Combine 3 cups of water with 1/2 cup white or apple cider vinegar, and mix well. Next, add 1/2 cup of baking soda, and combine to form a paste. Use a spatula or paintbrush to spread the paste in the oven. Let it sit for several hours or overnight. The mixture starts to lift up the grime, making it easier to remove. To finish, use water and a damp cloth or scrub pad to clean the oven. Rinse until all traces of the baking soda mixture are gone.