"
It's not a cure all but definitely reduces the overall parasite population.
"
Of course this is true, if you have 1000 parasites and you kill only 1 by using a zapper, your statement is still true.
"
I would combine it with some antiparasitic supplements for best results.
"
So that there is no way to know what is efficient to kill parasites and what i not, and sellers can continue to get rich selling useless treatments/devices.