I will say that it has worked for me. Last night I zapped, and despite not taking any parasite herbs in a week, I have already seen parts of a parasite pass thru this morning. I'm using the $10 zapper, and it is quite helpful. Last week I used it and during my Liver Flush I passed several flukes and seed-like parasites that I know were not food stuff. And all of this is a month after completing an herbal parasite cleanse.
If you plan to use it for 6 people, I'd suggest getting 2 zappers, or at least a lot of 9V batteries.