Hello, I'd like to report my findings, of what I am fairly certain was poorly preformed attempt to put your application into practice.
Let me first explain our clinch defense if I may.
We grab the elbows of our opponent, as their arms are around our neck, trying to pull us down. we keep our elbows in the center pointing down, and we place our elbows into the knee strikes, really hurts to be the one kneeing.. as we detect openings, we will land punches and than quickly regain the grip.. when we detect their balance is compromised, or they are distracted enough.. we will take a big step under them, and strike up through their throat.
In my attempt to implement your application:
I was holding onto the opponents elbows, in a cross handed grip,
(The reason we keep the grip on, is so that they can't release the back of our neck and launch an elbow, which can happen blazingly fast.)
and when he went to launch a knee, I would use the striking motion you described, in my lineage called double gan sau, and I was surprised how well it dissolved the knee thrown at me! but since I had no grip on their elbows, or arms, they were able to strike me the moment I left contact, almost meeting me to the strike.
without the elbow I was very impressed by this strike, and I realize I wasn't able to implement the biu tze movement which perhaps is meant to deal with an elbow attack.
Thanks for your time.