Well, the Zapper you are refering to claims to be modeled after Hulda Clark's Zapper Circuitry. To my knowledge, that is not true, because I have disassebmled and analyzed Clark's Zapper two years ago: It is simply a microcontroller based rectangle wave generator with variable frequency (about 10k to 500k Hz as far as I remember) and variable voltage (5-15V) output, positive offset. Also, all the new models of the Clark's zapper do exactly that, only with new slick outfit and illumiated displays. Clark proofed via experiments that a weak electrical current with a specific resonance frequency belonging to specific parasites weakens them, so that the immune system gets a chance to act. It is the mechanical resonance of the parasites that is stimulated through the electrical current. As an analogy, it would be like you are hearing a very loud sound with a high pitch that makes your head feel explode, thus rendering you unconscious.
On the contrary, the Zapper you are referring to, according to the homesite, has a fixed "feel good frequency" (red flag) of 15 Hz and built in magnets, crystals, "moebius" coils (difference to a standard coil?) and orgon producing material in it. It is therefore not even similar to Clark's Zapper, because of the fixed frequency. Also, the electrodes are only a few centimeters separated. Parasites, however, mostly hide not in your hand. The current must flow through the appropriate places.
Everyone using Orgon generators should learn about the benefits and also the dangers! There's a lot on the internet! I also suggest reading the orignal books of Clark et al.
Maybe this specific device has positive effects - but likely not because of Dr. Clark's method. With this short review it seems to me that somebody uses the popular names "Zapper" and "Clark" to spare the marketing costs - parasite-like I should add.