Thats pretty sweet. I would like to have the confidence to defend myself with a shirt. However, I dont think it is necessary as a weapon. When I think of a weapon, I think of some type of object being an extension of your reach. The shirt seems to be a good object to defend yourself with. But in those defenses the sifu is using, he does not even need the shirt. He is doing more work than he needs to; he could just strike or use a lock, to get a similar effect.