Yesterday, while cleaning under my kitchen sink, I found an old SOS Oven Cleaning Pad I purchased ages ago. On a whim I decided to give it a go and was amazed at the results. We've lived in our house just over 8 years and I've only ever cleaned the oven once (for whatever reason, this is one cleaning project that never occurs to me), so things were pretty bad. I couldn't get everything up but am shocked at how much I managed to clean, and with fairly little effort.
In terms of method, I did some minor scrubbing and then closed the oven and walked away for an hour to let the cleanser soak in. When I came back to wipe down with a plain, damp sponge, most of the grime came up. I did a second round on a couple of the more caked-on spots.
ETA: So I looked for this product at my grocery store today and couldn't find it. Now that I'm googling, I'm thinking they might not even make it anymore! Product recommendation fail, LOL.
Gah, I was ready to hop the in the car to head to ACE Oven cleaning is on my monthly list, so it usually doesn't get too bad and I just use a baking soda scrub. I do have one or two places with burned on oil though that I can't seem to get off.