tft wipes. They are moistened and safe to use, don't rub too hard either. Don't try putting resin or whatever on it and I agree deport the kid to the furthest away place you can find.
My sister once joked (to her it was funny) with a permanent marker letting on to draw on my tft, one mm away from the screen she was... I broke into a cold sweat. Of course nothing compared to the sweating and running she did trying to get away from me afterwards.