I like it because the wife doesn't kick me out of the house for using it. I understand it does not contain fancy additives for lubrication, but seems to clean well metal parts well enough. And, it doesn't seem to eat my skin like some of the solvents.
I don't seem to have rust in my bores... maybe it's ability to mix with water fades over time after you apply it (maybe that component evaporates or breaks down?), after which it is just an old fashioned oil?
Just guessing of course.