I reckon the factory finishes them with powder, it's stronger than most 2 pack paints iirc.
And yes, abrasives to deal with hard coatings on top of soft aluminium, sounds a challenge for sure.
There is some stuff, Benco C17, or you can make a home-made mix- check out this guy's how-to:
https://www.youtube.com/watch?v=tQkzpCBbXfM
It's a bit organic... but uh... it sounds only slightly more dangerous than your 'potion'