An Omnia oven is a self-cleaning oven that uses high heat to clean itself. The first thing you need to do is remove any food or grease from the oven. Then, turn on the self-cleaning cycle and let the oven run for two to four hours. The high heat will cause any dirt or grime to loosen and break down, making it easy to wipe away. When the cycle is finished, simply wipe out the oven with a damp cloth.