Cream of Tartar is supposed to work. Here's a link:
Here's a post that might help - https://www.diynetwork.com/how-to/maintenance-and-repair/cleaning/how-to-clean-aluminum
Aluminium pans go a grey colour with age and should not have the surface scrubbed in any way as Aluminium is not good to be ingested , and it might be if tiny bits are left in anyway. You should only clean them with with Dish soap on the inside. Best wishes
If they’re coated, like Teflon or other coatings and it’s starting to peel, then it’s time to treat your health and buy a new pan.
Between the aluminum and the coating, both of those are not healthy to ingest.
Hi Gayle: What I use is a paste of vinegar and cream of tartar (the dry stuff). Make a paste of vinegar and cream of tartar (use just a bit of vinegar at first as the cream of tartar sort of melts) and put it on the gunk. Maybe start out with 3 tablespoons of cream of tartar and a 1/2 teaspoon of vinegar. Add more of whatever to make a paste. It should stick to a vertical surface if it's thick enough. 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.