Why would you need to clean a computer...? Maybe the screen, but a soft T-shirt can take care of that...my macbook air is still shiny new after several months of carrying to classes etc...without any superficial cleaning treatment.
100% cotton baby diaper, slightly damp, for the screen. The rest of the Air gets the same treatment, unless it gets gooed, then I use a baby wipe to clean it. I NEVER touch the screen with anything but a 100% cotton diaper. I'm thinking microfiber would be just as good.