Cleaning LCD Screen

[EagerToLearn]

I need to clean my computer's screen but the rag that they gave me when I bought it (the ones you use to clean glasses) does not work. The problem is that a lot of my family members eat their dinner in from of the screen and for example, when someone eats a soup, the contents splash on the screen and dry up as a hard crust. It's really nasty and requires some scratching to remove but I don't want to touch the LCD screen since I heard that can damage it.

Any suggestions?