I've just got a CRT rear projection TV, it was cheap, but because it has stood around unused for a long time the screen is filthy. I've read the manual and it recommends that the only form of screen cleaning is to pat the screen with a dry cloth. This isn't going to work as the screen has been splashed with something (tried a small area with a damp cotton bud and it did seem to come off) and then wiped with a dirty rag or similar leaving loads of smears. So what is the best way to clean it, the screen seems to have lots of fine vertical lines in the surface. I'm completely new to this so any help would be appreciated.