In Praise of Ammonia: Ammonia is wonderful for cleaning and cutting grease and is very inexpensive to use. Mix half and half with water in a spray bottle, spray, then watch the ammonia do the work, it's amazing how well it cuts grease so quickly. I haven't found anything yet that it doesn't work on, just DON'T mix ammonia with bleach, EVER!
You can also put it in a glass bowl in your oven over night and just wipe clean within 24 hours. (Really messy ovens may take longer.)
Editor's Note: Ammonia is the active ingredient in many bottled cleaners. Make sure you use it with ventilation. It is great for removing old wax from linoleum floors, too.