1st time zapper, Help!

I've been following the cleansing site for a year or so and have only done one 30 day cleanse with Humaworm a while ago. I finally bought a Z4e Zapper and started 2 nights ago before bedtime. The zapper did not come with instructions, so I did the 7 on 20 off cycle 3 times per Dr. Clark. I did one cycle @ 30khz, the next @ 2.5khz and the final one @ 15hz. I could feel the zapper in my hands working(cool). Now I have developed an entire body itch that got me worried. Is this normal? I'm waiting on a new order of Humaworm to start but the zapper came in 1st, so I gave it a try. Am I doing something wrong with the zapper or am I driving the "critters" out of me?