Re: how do these frequencies really work here?

Zappers rarely, if ever, kill organisms through frequency.

They kill primarily through the introduction of metal ions. Copper is known as a strong anti-bacterial, for example. Silver is as well.

This is why lower frequencies are said to be more effective in a zapper. Lower frequencies are turned "on" waveform-wise much longer, giving more time for the positive ions to be released.

However, there are bacteria that rely on copper to survive, such as those in the Borrelia family. Many fungi and molds also require copper. If you are one of the poor souls infected with them, you will temporarily feel well from a zapper usage, but then will steadily worsen. You will be in actuality, feeding your unwelcome visitors.

Another danger is that copper itself can be poisonous. Those with diseases like Wilson's disease should not use a copper electrodes. Use graphite electrodes instead.

Zappers may also kill organisms through other more minor ways, such as hydrolysis, induced magnetic fields, and the creation of heat.

The second in particular is probably more important than we realize. Zappers produce a positive magnetic field, and this can disrupt tiny molecules in parasites' exterior membranes, possibly enough to kill them. If the molecules on their membranes are positively charged, the positive electrode will repel the molecules; if the molecules are negative charged, the positive electrode may "pull" the molecules away from the cell. Opposites attract.

But overall, frequency is not an important factor in the zapper effect.