I use oven cleaner.
Saw a video of a chef who used oven cleaner on his pans.
Hi Rachel: What I use is a paste of vinegar and cream of tartar (the dry stuff). Make a paste and put it on the gunk. Let it sit for about 15 or 20 seconds and then scrape off with a plastic putty knife or one of those plastic scrubbies. You may have to do it a couple of times if the gunk is thick, but usually not. There is no smell and it is environmentally safe. Good luck
Spray the pans w/hydrogen peroxide then sprinkle on a layer of baking soda. Let sit overnight then just wipe them clean in the morning. Easy breezy!