PC-6 is a great setup point. I can easily be touched during a fingerlock or any other grappling move. I will usually try to use my pericardium there. Holding this point during a strike will magnify the effects of the strike.
Experiment with PC-6 and you can see the different results for yourself. Keep track of what you are doing, then look for techniques in your style, that have become automatic that these techniques can be worked into.
The other meridians in the area are Liver and Kidney. If you have any questions of would like more information our our course visit the links below.