Saline solution necessary
I was about to return this, just didn't seem to work even on #10 setting.  THEN I read you need to use saline water, not just plain water!! WOW, not only did I get the 'zap' I expected, but the unit actually made a buzzing sound. I was getting none of that with just wet fingers.  I am now using the canned saline solution.  Even got the white bubble after about 10 seconds.  I'm hoping to have much better results now.  Just remember you HAVE to use saline/salt with the water to make this work.
Rating: 4 stars