About ten years ago or so when I first learned about this stuff I called a distributor, I believe out of Colorado, and talked with him about it. He passed on the story that it was a coal oil product developed in Germany as an all in one lube that would help to preserve metal, oil, wood, and even serve as an antiseptic aid for minor cuts.
Ever since then I have used it on my rifles, clean with it straight for the first time and start counting the patches, you swear you will never get a clean one to come out. Of course, eventually you do. I have used it on my leather bags, stocks and all metal surfaces on my rifles and pistols, on my own cuts, and even used it to cure ear mites in my Springer Spaniel and yes it worked super for that.
I love the stuff and although I generally clean with just straight cold water in my rifles now they always get a Ballistol soaked patch run through to protect the bore and a final wipe on the outside. My bores are clean and protected with the stuff, simply put, it just works.