[Big-Foot]

If I had the bucks for a Kirkham, I would ask Kirkam if this stuff is safe to use on their cars.

I'm thinking it's a diluted acid as well. I've used something that cleans aluminum and removes oxidation in the past on my motorcycle engine. It worked fantastically! The only kicker was that the aluminum I used it on now oxidizes 10 times worse and 10 times faster now and you have to keep chasing after it with the cleaner (acid). I finally got smart and started spraying it down with WD40 after cleaning it and then wiping it all down. Now it still oxidizes, but at a much slower pace, but the WD40 attracts just that much more dust/dirt.
In the long run, I took a negligible annoyance and turned it into a major headache.