Marvels Mystery Oil

What exactly is this stuff? Friends at work swear by it. But what is so mysterious about it?
What is it supposed to do?
Does it even work?
And what would work better?
Thanks for the info about it.

I have used it to clean gummed up carberators on motorcycles, by using a couple oz's per tank fill. Worked great. I also use it as a light lubercant and in my air tools. It works also as a penetrant on rusted bolts. I always have some handy..JMOP..