I know your problem. I used to suffer. I bought a Beck zapper about 3 years ago and hardly used it because of the mean rash.
Lately I have committed myself to the Bob Beck Protocol and I decided that there has to be a way to solve this nasty rash thing.
Here is the recipie that really works for me every time trust me. I get very little rash now and it is gone within 1 hour!
"3% Peroxy Gel"
1 1/2 cups aloe very gel, (from health store), 1/3 cup of glycerin (I got it at a herbal store, maybe pharmacies will have it) and 3 Tablesp. of 35% H202. If you are using 3% H202 multiply the amount by 11. You won't need this much but I somehow took a third of the quantities.
Wash the wrist gently with soap and water before zapping. After zapping apply your ointment and watch the rash fade; mine is gone within an hour. Keep your ointment in the fridge.