Looking through my replays and I remembered these two guys.
These leg takedowns use a lot of grip switching especially in the first replay where each hand will grab, ungrab, and regrab.

monkeyishi is definitely right in that the consistent grip switching will easily trick players who are dependent on their ghosts too much.
Also i find that when you have two grabs near eachother, ungrabbing one will give a small accelerating force in your movement.