Silly question, I know. However, I used to use Whoosh but then I read that Apple does not sell it in their stores or online because it can cause issues with the anti-reflective coating (and on iPads the oleophobic coating.) Do you guys use just plain old glasses cleaner or what? Usually I just use the microfiber that comes with the Retina MacBook Pro (mine is a Early-2015 13") but sometimes things get on the screen that require some liquid along with a microfiber. I just got a new screen on my rMBP (covered by Apple because my rMBP is still under its original warranty) because there was some dead pixels that just suddenly showed up on the old screen, so I am trying to be as careful as possible. I know that spray on the screen does not cause dead pixels, like I said just trying to be careful and not ruin the anti-reflective coating or anything. Thanks in advance!