An important parameter is missing, the difference in current density between what was in the slide and what is in a human. It is easy to kill microbes in a slide because the current density is so high. (Current density refers to the amount of electric current per square millimeter.) In a human the current spreads out and greatly lowers the current density. So positive results in a slide do not reflect equal effectiveness in a human. The lab test only shows the possibility of effectiveness in a human which is a first step.