Steel screws into Aluminum + time = chemical bond, no?. Do any of these penetrating oils actually affect the bond? It seems unlikely. But, maybe they keep the bond areas from reforming if one can gradually break some free?
The 50-50 mixture of ATF and Acetone is interesting too. The acetone would flash off quickly (unless it gets down into the threads.) Maybe it “wicks” the best? Slowing flash-off may be at the heart of mixes also containing mineral spirits or turpentine. I would wonder if xylene might not work well, to mix with ATF? Xylene has a slightly “oily” characteristic to it, to begin with.
BTW, PB Blaster should be available at Wally World, Home Depot, Menards, Lowes, and many hardware stores and farm supply stores.
There is no chemical bond formed.
There may be some electrolytic corrosion of the Aluminum. The corrosion products occupy more volume than the metal, so it gets tighter. Heat is your friend in that case.