Go for the zapper with the copper hand holds. They work the best.
I zapped at the same time as doing the parasite cleanse. To help mop up any bacteria and viruses hanging around. I started zapping 2 weeks before starting the parasite cleanse and passed many parasites. When parasites die, they have viruses and bacteria in them that at some time were in you, and they are released. The Black-Walnut hull tincture is good at killing of a lot of these in the gut. It is anti-bacterial, anti-fungal, as well as killing parasites, and also has many other properites. This is natures way of protecting the seeds of the walnut tree when they are being produced, and when they fall from the tree, and lie on the ground. Stops funguses rotting them etc. And the few of us in the know harness these properties to our advantage.