Once you have it clean, going forward, use a soft brush, like something you might clean camera lens with or one of thoe bulb things to blow air that comes with most camera cleaning kits to keep dust off. https://www.reddit.com/r/mac/comments/1j0ihpc/comment/n2bhtko/?utm_source=share&utm_medium=web3x&utm_name=web3xcss&utm_term=1&utm_content=share_button