I'm considering making Dr. Clark's updated (1000 Kz frequency) zapper, but would like comments from those who have used it, first. How efficient is it for zapping parasites? I'm wondering because my husband is ill (though getting much better through Dr. Clark's methods) and should have a zapper to further his progress. So, we're undecided whether to make one (I have experience making electronic circuitry following plans only; I can't think it out without a plan!) or buy an inexpensive one yet an efficient one.