Just saw this You tube clip:
But it is different than how we do it.
Basically, in Ai Hanmi - say Uke grabs my right hand.
I would step to my left and break ukes grip on my right wrist by rolling down and grabbing with my left free hand to 'tighten ukes wrist' so they let go.
Then I would continue to hold uke with my left hand, and take my new free right hand and 'atemi' uke and step under...
At this point is where the Sankyo bit would come in or the 'cut' and throw.