I'm trying to find a video for you. Tell us about your fancy nikkyo in the meantime. It's just a discussion, so you don't have to be a Shihan to offer something.
I am lousy at explaining this, but bear with me. Starting with katate tori hansha, step hantai tenkan and use your cross hand to break the grip like you are about to do an ikkyo. As you start to turn uke's arm over, use the same side hand to lock your thumb underneath uke's thumb. Move directly in to uke and spin your arm underneath the uke's elbow so you are standing side by side, with uke's elbow locked against your rib, and just lean both your hands on the back of uke's hand and pull back. The lock is solid and puts you in a good escort position if you just want to walk someone out the door. Plus I've yet to find anyone who can weasel out of it, no matter how flexible their wrists are. I usually teach it from that attack, but it works even nicer from yokomen uchi. I love the economy of movement with it.