Yeah, I've been learning the 2nd method Jakob mentioned. The elbow doesn't bend all that much, I have to twist my hips pretty hard to get into the right position so I don't get hurt. I practiced quite a bit by just doing forward rolls from that position. The nage has to have enough control to know when to let go to do the forward roll correctly. Then I slowly progressed into letting him hold on a little longer each time.
It's very much like kotegaishi, but it launches the uke off the ground. What a rush!
But... don't make the mistake of trying it with a nage that has never taken the fall. They won't know when to let go and will tweak your wrist pretty hard.