I have plugged two prong plugs into my conditioner in similar circumstances , I could tell no ill effects, I can't think of what they would be theoretically. I have often used cheater plugs to reverse 3 pin plugs to deal with grounding problems or because they sounded better that way. Still have a direction finder that is suppose to tell you which orientation is better. I stopped using my conditioner after I got dedicated lines and compared my system with and without, but results will vary.
