Yes, I'm not sure new motor oil is the best thing to get on your skin, but used motor oil is much worse. My problem with motor oil is it migrates away from where it's supposed to be too easily. Motor oil in its intended environment is spray, splashed or pumped to where it's supposed to be. It's not expected to just stay there. Therefore, at least for pistols, I like some form of grease or paste.
Here's where I out myself: I tried Froglube (gasp!). Someone gave me some so I figured it was worth a try. It was the paste. It was easy to apply, didn't smell bad and seemed to do what it was supposed to do. I had no problems with my guns instantly rusting, jamming or exploding. As far as cost, the stuff isn't any worst than any of the other greases marketed for guns. That said, I agree that their marketing is pretty annoying and I don't really care if a SEAL developed it. I'd rather hear that some mechanical engineers and chemists developed it. On the other hand, if it really is the same as that stuff for carnival rides, I'd imagine there are some pretty major sheer forces involved so maybe that's not a bad endorsement (*shrug*).
I've also tired Militec 1 grease which is petroleum based and I thought that stuff sucked. It was hard to clean and at least when cold, caused cycling problems with some of my guns (a SIG X5 in particular).
Finally, the one I really like is TW25b which is what SIG used to put in the case when you bought a new gun. It's easy to apply, clean up and is implicitly endorsed by SIG. On the other hand, it's expensive.
People seem to over think this stuff.