A good blast to the groin, solar plexus, throat, palm strike to the chin, with fingers in a claw towards his eyes, or a kinfe hand stride to a very sensitive area about 4 inches below the ear lob, can loose up and make cooperative your attacker, when you apply whatever qin na fits the situation of where he is in space and where you are in space and also what limb presents itself readily from this softening him up.
What kind of qin na requires to much thought in fight, I just apply whatever fits, on whatever presents itself, with the above softening up being the first order of business. It can come from many sources in my training backgroud. I don't care waht source, just that it will emerge without thought.
Best regards,
James