I use a variation on this for cleaning oven racks. Get a few old towels, a bucket and some rubber gloves. It is best to do this outside. on a patio or paved driveway, but I have done it in a bathroom with the window open and the ventilation system on full-blast. Put one of the old towels in the bottom of the bucket and pour in sudsing ammonia until the towel is saturated. With gloved hands, remove the towel and place on the patio or in the bathtub. Place the rack you want to clean on top of it. Then take a second old towel, repeat the procedure with the ammonia, place that towel on top of the oven rack, so the rack has two ammonia-saturated towels covering it completely. I usually do this in the evening and leave it to work overnight. The next morning, remove the towels and rinse the rack. It will be sparkling clean, with very little. if any wiping or scrubbing needed. I did this with the racks from a really badly abused electric oven. Tenants had left it in a crusty, greasy nasty mess. I also heated the oven (with one of the racks placed at the mid-point) to 200 degrees Fahrenheit, then turned the oven off, placed a shallow glass baking dish filled with ammonia on the rack, closed the oven and let it work overnight. This took off an amazing amount of the gunk and grime in that oven, though it did require quite a lot more scrubbing. It was worth it!
I use a variation on this for cleaning oven racks. Get a few old towels, a bucket and some rubber gloves. It is best to do this outside. on a patio or paved driveway, but I have done it in a bathroom with the window open and the ventilation system on full-blast. Put one of the old towels in the bottom of the bucket and pour in sudsing ammonia until the towel is saturated. With gloved hands, remove the towel and place on the patio or in the bathtub. Place the rack you want to clean on top of it. Then take a second old towel, repeat the procedure with the ammonia, place that towel on top of the oven rack, so the rack has two ammonia-saturated towels covering it completely. I usually do this in the evening and leave it to work overnight. The next morning, remove the towels and rinse the rack. It will be sparkling clean, with very little. if any wiping or scrubbing needed. I did this with the racks from a really badly abused electric oven. Tenants had left it in a crusty, greasy nasty mess. I also heated the oven (with one of the racks placed at the mid-point) to 200 degrees Fahrenheit, then turned the oven off, placed a shallow glass baking dish filled with ammonia on the rack, closed the oven and let it work overnight. This took off an amazing amount of the gunk and grime in that oven, though it did require quite a lot more scrubbing. It was worth it!