Just to be thorough I retried the zapper after 18 years.
I can say with sureness it's pure bullshit.
If your body is polluted to the brim with filth and pathogens you might derive some benefit, but eventually nature takes over and 'infections' will keep coming back until you learn how the body works.
All of the zapping salesmen and crew are trying to make money, or they simply do not understand basics about natural medicine.
How in the world did the human race survive without zappers for millions of years.
Do the real work, clean your body out properly and these zapper toys are completely unnecessary.