I can't guarrantee this definitively but I always thought ColdFire "corroded" Al bottles because it is a bipolar solvent, a "soap" Al2O3 is an impervious insoluable compound that protects the (very reactive)surface of pure Al, if you polish or dissolve this very thin corrosion layer, another will form, and another......til it is all gone.
As for the argument about soap v Halon. I have clients with aquired brain injuries, one from being trapped in a space with limited oxygen, not long, but long enough. Choose your poison, for me its "soapy water"