Clean Grill Rack and Oven While You Sleep

Lay a barbecue grill rack on the lawn overnight, the dew will combine with the enzymes in the grass to loosen any burned-on grease. Try it with messy oven racks, too.

For inside the oven: Put about a half inch or so of ammonia in a glass baking dish (don't use metal) and leave it in a cold oven overnight. The grease and gunk will scrub off easily. It's a lot cheaper than oven cleaner.