for cleaning up stainless steel.

https://www.amazon.com/Bar-Keepers-Friend-11510-All-Purpose/dp/B07DFQQWH1/ref=asc_df_B07DFQQWH1/

I'll have to see if I can find it locally. (I hate Amazon)

If you can't find it at the Walmart, or a grocery store check the hardware store. Lowes, Home Depot.

By the way, it is about the best thing I have found for cleaning old silver. I tried silver polish, the smell gave me a headache.

old scool steel svrubber or just call it patina?
next time just use foil and toss it.

Should have used aluminum foil. Oh well, next time.

I would try putting some water and baking soda in it, then heat it up in the oven.

When you remove it from the oven scrub it with more baking soda. If still not clean add vinegar. Still not clean up it to salt. Then the bar keepers friend. Then oven cleaner.

If none of that does not work to your satisfaction, congratulations! You now have an oven drip pan and have to buy a new cookie sheet.

So we'll try to save it.

pretty much anything baked on to any pan. If you have a garage that isn't too cold, you could leave it there.