I spent almost nine years flying jets in the Marines. That doesn't make me a jet engine mech, but I have spent a fair amount of time with a bunch of the real ones. For you USAF guys who are wondering about this, keep in mind that we didn't have separate "maintenance squadrons," all basic and some I-level functions for USN/USMC aircraft are performed by folks assigned to the flying sqdn.
Anyway, I've talked engines, oils, hot rods, you name it with these guys. A few times I heard the story about the guy who had tried the jet engine oil (we used MIL-L-23699 for the most part) in his car engine, and the story always ended up the same way: prompt destruction of the victim engine. Keep a couple things in mind. First, this stuff is of very low viscosity; it looks like and almost runs like water. A little thicker, but not by much. Second, and I think more critically, it's designed to lube and cool very high speed, very hot bearings in an environment never polluted by blow-by combustion gasses. To my understanding, it has zero ability to neurtalize acids that result from blow-by.
I would be very cautious about trying this, and would probably save it as a last resort after all other modes of cleaning had failed and I had little or nothing to lose by trying it. I would never use jet engine oil in a good engine as a routine cleaner. Yes, I know how esters are naturally good cleaners, but I think there's also a good chance of finding a cure that's worse than the disease.