I've been able to counter some bad nikyos over the years, but usually with sankyo or nikyo itself. I've not seen or heard of a nikyo counter that can throw someone back ten feet. I can understand, I think, how to transfer uke's power to the opposite hip, but I'm drawing a blank after that. Please tell me more. Is this something William Gleason does?
I played around just a bit with something like that. Probably isn't the same as what Rob is doing, though. I had my uke put me in a nikkyo. As he applied more force to the nikkyo, I used my suit to let that force go through the wrist, through the arm, through the shoulder, down across the back, into the opposite leg and then into the ground. Well, I got as far as the back but I couldn't get the force to go through the leg into the ground. (As I've been told before, my lower back is a mess. Still working on it.)
What I found while doing this was that the energy coming in was sort of spiraling through my body and getting stored. As more force was applied, more energy came through. So, in a "I wonder" moment, I released all the energy back into uke and it popped him back a couple steps. Was really neat.