You might get a runny nose or scratchy throat from killing off the parasites. It feels like you're getting a cold. If you dont have the bucks right now, use the 9 volt battery. Wet your fingers, (keep them wet) hold one terminal with the index finger of one hand and tap the other terminal with the index finger of your other hand. Do it for at least 7 minutes on and 20 minutes off x3. It works. It will make your fingers tired, but do it anyway. The next best thing is to get one of the simple zappers when you do have the bucks.