I am not sure why you can not see the image. Anyone else have this problem?
I have not seen any indication that the electric signal would make parasites or any organism stronger. Only that the ones closest to the ground or negative electrode are less likely t be killed.
If you are doing battery tapping, keep constant contact with the negative, tap the positive, keep the rate steady, and because it is probably less effective, keep tapping for at least about 15 minutes, rest about 20, and repeat at least 3 times.