>- The effect of a zapper on a jar of water has no relevance
Yes it does. The body is mostly water. While the body is definitely more complex, it is known that "good zappers" can even reach into the gut, contrary to Dr. Clark's claim.
>- Salt will also kill bacteria in a jar of water
Only in concentrations that would be damaging to the human body. Gargling with salt water is a known treatment for throat infections but you should not dare take a lot for internal infections.
>- have to be used ... with respect for proper and safe dosing.
I am in absolute agreement. The difference is in which zapper you choose.
>- used various zappers, like the Z4ex from ebay
Yes, I like the Z4EX when one has a very limited budget. Any zapper can produce benefits but any zapper can have limitations too.
We used to produce a zapper in the same price range as the Z4EX but dropped it in favor of our newer models that we find to be more effective.
One possible reason that you are having difficulties is that while helpful, the Z4EX, even with 3 different frequencies, is not effective enough in killing off the microbes that are attacking you. I tried the Z4EX in the water test, No match for the CC2 but again, the CC2 with paddles and pads is almost $200 US.
I wish that we could make it less expensive.
>- like the battery zapping
Yes, this is something that people can do most anywhere in the world. Some people actually try tapping on an automobile battery.
It should always be remembered that the zapping can not be done just once but needs to be repeated 3 time with 20 minute rests between.
Always keep the metal off of your skin by using a wet cloth or wet paper towels.