Here it is: Step 1: Sprinkle a thick layer of baking soda over the baked-on mess (your oven needs to be completely cool for this). Step 2: Then, spray the baking soda down with water (white vinegar is even better). Step 3: When the baking soda dries out, spray it down again.Step 4: Come back in a couple hours, and scoop out the baking soda. All of that stuck-on mess should come right out with it (with no scrubbing required).Step 5: Wipe down the bottom of the oven to remove any remaining baking soda, and your oven is ready for use again.Filed Under: Clean It.tep 4: Come back in a couple hours, and scoop out the baking soda. All of that stuck-on mess should come right out with it (with no scrubbing required). Step 5: Wipe down the bottom of the oven to remove any remaining baking soda, and your oven is ready for use again. Filed Under: Clean It.