Hmmm. Any time there is some bolt sticking out, and a vice grip won't do it, I take a cut off wheel and cut a slot in it.
Then, with a nice beefy fat flathead screw driver that fits the slot snug, and a crescent or wrench, try backing her out.
Just got one out last week this way.
Sometimes it works, sometimes not.
Depends on how much bolt is hangin out, and how tight that joker is.
PB is awesome. Nothing I've used compares.... though, I think Jim knows of some awesome stuff too, though I've never used it on threads.