The frequency just goes through your body and kills the critters that it reaches. The 1st time I zapped, no plates used, my stomache sorta swelled up a little and then I started burping. Happened the second time too. That's when some of my tummy problems started to ease.
Think of it this way: zapping with the plates is for specific, like if you have liver problems or the flu. zapping without the plates is a general all over zapping.