The spray lubricant WD-40 lubricates items, and while it's meant for cleaning car engines, it has a number of uses around the house. Use WD-40 to clean stuck-on grease and food bits from your oven racks.
Remove the oven racks from the oven and take the racks outside. Thoroughly coat all sections of the racks with the WD-40 and let the lubricant sit for at least five minutes. Lightly scrub the racks with a wire or nylon brush.
Rinse all traces of the WD-40 from the oven racks and pat them dry with paper towels. Apply more WD-40 and scrub again if the oven racks are still dirty. Rinse and dry the racks completely before retuning the racks to the oven.
Only use the WD-40 to clean the oven racks outside or in a well-ventilated area. It has a harsh scent, which may make you feel nauseous or dizzy, especially when such large amounts are used.