Uhh,
Tough one. Some manufacturers recommend using Rubbing alcohol to clean the surface of the LCD, together with a microfibre cloth. Some manufacturers say NOT to use any alcohol or alcohol based solutions as they can damage the surface? Go figure? Anyway I know that the LCDs are cleaned with rubbing alcohol when leaving from the factory. But I also think prolonged use of alcohol could damage the surface.
In any case DO NOT use any Glass cleaning products/ benzin based products/ nail polish remover... Your LCD = plastic so any of the forementioned stuff would definately kill it. Also never spray anything directly to the LCD, but allways to a cloth. Never use paper to clean the LCD, as it will scratch the surface.
There are some specialized products for this though, for example klearscreen
LINK
If you cant find any specialized solutions, I would try with some rubbing alcohol and a microfiber cloth. (thats how I do it).
Hope this helps!
-DaFinn