Rather than buy these expensive brushes, which slowly lose their punch, go to a cheap store (dollar store?), pick up a soft brush (could be a paint brush) and some drier clothes, then rub the brush on a drier clothe and you've got the same thing,...and, it's renewable! Drier clothes are great for rubbing down the CD tray and other areas that accumulate dust. For years housewives have used them to quickly remove lint from the lint trap of the drier. They are quite amazing!
Oh, by the way, rub a drier clothe on the little brush on your laser cleaning disc to make it more effective!