I don't think Windex would hurt a perfect flat CRT monitor, They don't have any glare as it is.
As for my monitor... I use this 3M stuff, it's for Autocar glass, I spray it on there and clean it off with some downy paper towels.... Works well and I have not noticed any scratches in it at all. Ive done this for over a year. I have the ViewSonic PF790, so that might have something to do with it, being flat and all.