Anything with a really low ph should help break up the aluminum.
I've heard both ketchup and coca-cola will disolve aluminum.
You could also try using muriatic acid.(watered down if needed)
When i was a teen,we used to make pop bottle bombs (muriatic acid-tin foil balls)
place tin foil balls in plastic pop bottle, pour in acid and screw on the cap.
the acid eats the tin foil and the gasses inflate the bottle till it explodes. (I"m sure if you look, you'll find vid's on youtube)
heres what i suggest. (its nasty stuff, and the gases it's gonna make are even worse.)
if at all possible do it outside. If not make sure the kitchen is well ventalated.
I would use a q-tip so you can limit the amount of acid your using. just dab small amounts of acid on the tinfoil itself. i would also spot check on the reverse side of the panel to ensure the acid won't remove the non stick coating.
you'll see it working instantly (bubbling,turning the tinfoil black etc) work on a small area at a time, removing excess as soon as possible.
Now the thought of acid in your stove might scare you, but theres a really simple way to neutralize the acid when your finished.
either baking soda or laundry detergent will break it down and render it safe.
I use this and other acid's to etch my damascus knives and cuttlery.(many being used for food) once its neutralized, these no risk of injury to the stove or people eating out of it. residue can be rinse clean with soap and water.
muriatic acid can usually be found in the paint section of your hardware store for approx $3.
If the plan is to replace the bottom panel, what ya got to loose other than $3.
