Between Thanksgiving and Christmas a lot of holiday cooking made a lot of ovens a mess. To give your oven a good cleaning, pre-heat it to about 200 before going to bed. Put a bowl of ammonia on the center rack, close the door and turn the kitchen exhaust fan on low. The next morning you'll find the ammonia has softened the crusty burned on spills, and you can wipe them up easily with a damp rag. To clean oven racks and barbecue grills, put them in a plastic trash bag with ammonia, seal it with a twist-tie and let then soak overnight. The next morning wash them in the tub or hose them off. If you hate ammonia and live in warm weather, just leave them on the lawn overnight; evening dew and enzymes in the grass will do the job. And that's the On The House tip for today.