I failed to mention that the lawnmower is supposed to be turned off, with the lead removed from the spark plug, and only then do you pull the starter cord. It packs quite a punch when the motor is running flat out, because the voltage increases as the speed of the flywheel increases, so touching a running lawnmower..... while standing in water... would definitely be a humbling experience The fingers are also very sensitive, and a shock to the fingers is much more painful than one to, perhaps, the arm.

The device that we are building gives about 10 pulses in about 1 second. You have to then rewind it and repeat if necessary. On the arm it feels like more of a quick spasm than a painful shock. It is quite a bit less painful than a bee sting, and it doesn't hurt afterward either.