Cleaning your dish is often not needed other than for maintaining curb appeal. As mentioned above, clearing your dish of dirt and other deposits may help keep snow and ice from building up, but it won't typically otherwise improve performance. If you do decide to clean your satellite dish, do so gently using a soft sponge and warm water. Avoid using any cleaning products aside from mild dish detergent, as harsh chemicals may damage the surface of your dish. Ideally, you wouldn't want to clean your dish with anything you wouldn't use to clean your TV screen.