This pH-altered mineral oil was originally formulated before 1914, for use by the German Army. It was designed to be so general in its purpose that it would satisfy almost every requirement of the German soldier.
It was to clean and lubricate firearms and other metal equipment, waterproof and polish wood, condition and preserve leather, and was even supposed to be a remedy for minor wounds, skin abrasions, and rashes. Whether it prevents or cures sexually-transmitted diseases is not mentioned in its accompanying instructions.
To date, I have not yet used Ballistol to actually clean a gun, but after lightly lubricating my carry pistol I found dirtied oil creeping out from between several of the gun's joints. I added a little more of the oil, and found that it did indeed loosen and lift crud out of crevices. Further, being pH-altered, it seems to prevent the rust that forms from contact with human sweat; however, I have not been using it long enough to have made a real test of this feature.
Next, I used it on a folding knife that had sustained rust damage from exposure to Coca-Cola. The more easily reached oxidation had already been treated successfully with a rust remover, after which Ballistol caused the hidden remains to flow out of the niches in which rust persisted. Once that was gone, no more reddish discoloration has been observed, following subsequent oil applications. Further, after using the knife to open some taped boxes, Ballistol immediately and effortlessly removed all traces of sticky tape residue from the knife's blade with just a wipe of a paper towel.
In the cases of both pistol and knife, Ballistol has continued to act as a satisfactory lubricant, requiring normal reapplication at a rate of about once a week.
Since Ballistol does not seem to polymerize, I am not sure if I would recommend its use on gun stocks. A quick wipe of it will certainly make a stock gleam, but if it soaks into the wood, it may become as harmful to accuracy as it proves beneficial to appearance and waterproofing.
Ballistol is a good dressing for leather that should be kept as flexible as possible. Small amounts of it will keep a leather rifle sling in good shape. It would also be good for shoe leather, except for the fact that any oil will eventually destroy the cement that helps hold shoes together. In the WW1 era, shoes were assembled using hot hide glue, which is not affected by oil; however, nowadays shoe cements are plastic- and rubber-based, and oil reacts badly with them.
Ballistol is most definitely very bad news for wet-molded leather holsters. It will soften the leather to the point that it will no longer retain the pistol it is supposed to fit. Do not use oil, or saddlesoap, on any wood-hard, wet-molded holster.
Ballistol is a "creeping" oil. It cleans by flowing under dirt and lifting it from the affected surface. The creeping feature also gets it into hard-to-lubricate places. As a cleaner and a lubricant, it works very well indeed. It is, however, not "resident" in the pores of a lubricated surface, so it wears off in a short time, and must be replaced.
Due to its chemically-altered pH, it seems to be an effective rust preventative, warding off the effects of body salts on the metal it coats. But the Ballistol coating needs to be renewed fairly often.
Ballistol does some things quite well. You might like it. But be warned: Its odor is a bit unpleasant, with slight fecal overtones.
Oh, yes: It is no longer recommended as a cure for minor wounds, abrasions, and rashes. It is not manufactured to medically-pure standards.
I use Hoppes #9 for after shave cologne when I have a big date. Burns a little, but it drives those gun loving girls wild.