With Slapping Silk, after the downward slap to the thumb, try an insert. Extend the thumb on your left hand like you are hitching a ride, then insert it under the opponent's wrist and bring it up so that it is pointing vertically and slightly pronating the opponent's wrist, the right hand is rolling back toward you, with the belt laying over the back/side of the blade, then push your right hand downward in the general direction of the opponent's groin. The rolling motion, pulling with the left, pushing with the right, with the blade as the fulcrum, should act as an effective disarm. Continue the tech as usual.
Incidentally we know many of the same people, I am a student of Jim Dean and Jared Wihongi.
Lamont