Ever turn a torque wrench? Nothing really happens if you don't apply force...use your muscles. I'll have to try the loose hands, pulse, loose hands this weekend and see if getting those lug nuts off the car is any easier.
I believe his premise is that the forearms shouldn't be used to power the initial launch of the swing and the pulsing action is to create structure to allow connection through the different body segments. My hands are basically hooks when using wrenches that just provide a connection to what I am attempting to pull or push and not necessarily producing the force.