I've have all way's heard that Break-Free clp was one of the best for cleaning and protecting your firearm, One of mine is a WW 2 German Luger 1936 S/42, I just read on another site that you should not use Break-Free on earley Luger's because there finish is rust-blue which is "rust" and that using Break-Free will loosen the rust blue over time, Is he right? Should i stop using it? There are so many Oil's and opin's out there, HELP.:banghead: