Yes i have experimented the same thing, i have tried with the ultimate zapper and the blood purifier (+ handles + footpads) and depending on how many electrodes i touch, the current is less or more powerfull.
The problem remains : how to reach the "empty space" in the lungs, the stomach, the small intestine, the colon where there is not enough conductivity...
The zappicator i have seems to increase blood flow but maybe it needs more power to kill parasites...
What are the specs of the F165 ? How many V ? How many mA ? I know you can set the frequency.