Scientific studies have proven that Clark Zappers don't kill microbes. I highly recommend the Beck type Microbe Electrifier for systemic infections because it definitely kills bacteria and it stops viruses from infecting cells so they are more apt to be captured by the immune cells. And the Candida Zapper is the only thing I recommend for candida other than lowering your Sugar intake and increasing your Sea Salt intake. (supplement with Iodine if the salt is not iodized)
ps- the Rife machines also are just New Age toys