Someone posted another time that its a good idea to put the zapper on back of neck and stomach instead of the hands and feet, reason being that some infections just escape the current and goes to other places like the eyes (as far away as possible). Also if you are using it for a short time perhaps it kills some type of parasite and then the bacteria is making you worse or if you kill the bacteria the virus makes you sick, as for example Ascaris contains bacteria-fragilis that contains coxsackievirus. Hulda Clark uses at least 21 minutes on the zapper to kill bacteria and virus released when the parasites die.