Ooof! Just checked your post. Sorry to hear. I agree, even under best conditions, it might best be one person/one SteriPen. And yes, the on/off switch isn't the easiest. Not knowing about your problems, I nonetheless began to think I might need an alternative.

I caught on to the SteriPen because it was invented locally (Blue Hill, ME) From what I have heard about the inventor, he'd be VERY interested in hearing your story.