Cleaning burnt-on grease with ammonia

After asking this in multiple places and finding nobody with an answer I decided to test with the gunkiest cover. The handle came through fine. I'm not going to try the teflon pan.

Do not use on teflon! I tried that and all the Teflon peeled off. I had to throw out the pans.

If I'm understanding your method correctly, if you're worried about the handles being damaged you could use a smaller bag the covers the pan, but tie it tight around the handle where it joins the pan (and I assume isn't plastic). That way only your metal pan is exposed to the fumes, the plastic handle remains outside of the bag.

The other thing to try is the general advice when you're not sure if some chemical will damage some material. Dab a tiny bit on hidden or less visible part of the handle and see what damage it does.

You could try something like the above with your Teflon pan but it would be trickier. You could try using plastic wrap to seal the top of the pan before sticking it in the bag. You might need to tape it to make sure it doesn't come off.

Instead of ammonia, you should try "Barkeepers Friend" that stuff is great. It takes off the burnt on grease easily. It is very gentle of my pans. I own all clad cookware, stainless steel. It works wonders, and shines it up real nice. In response to Teflon pans, if grease is burnt on like you say, I'd say it's time to get new pans. Once food starts to stick to the pan, even after a rinse in hot water, it's non sticking powers are just about depleted.

Enamel coated roaster, stainless steel & ceramic Is safe to clean using ammonia & garbage bag. I put 1/4 cup of ammonia in the roaster & lid & tied up the garbage bag & put it down stairs. Brought it up stairs to clean a couple of days later, dumped it in the sink & rinsed everything in hot water. Rolled up the garbage bag & threw it out. All the burnt on grease etc on the outside of the roaster & lid, it just peeled off the roaster. I rubbed a scrubbie over it all to get at the hard to reach places: handles & rim edge. All clean...... looks like new. Can do the same with stove top pans & rings & racks from oven - I do over night for those. 1/4 cup of ammonia or less & put everything in a garbage bag & tie it up & place it out of the way over night. Come morning your clean up will be so easy. Rinse in hot water & wear rubber gloves & use a stainless steel scubbie to get at hard to reach spots for a better clean. Use in pots that got burnt on food.... overnight ammonia & alittle water: wash with hot water in the morning.