Oh, welcome to the CONSTANT BATTLE between me and my coworkers. THESE ARE NOT TOUCHSCREENS.
Anyway, I use a half and half combination of rubbing alcohol (the higher the %, the better) and distilled water. Distilled is very important. Dip a soft clean cloth in the solution, wring it out until it’s just barely damp, and clean the screens. If you Google what commercial screen cleaners are made out of, this is the combo you get. (Go ahead, check. It won’t hurt my feelings.)