I would use a mild carpet foam/spotter, just be careful cuz the aggressive ones will permanantly bleach the dash if you're not careful. Spray some on a rag and wipe it down. You need a product that will remove the silicones from the dash (silicone is what makes different products ie armorall, tire shines, any wax that isn't body-shop-safe shiney) I have used Dawn successfully, and it's a nice, mild cleanser. But it will dry up the vinyl/plastics, so follow it up with a non-silicone protectant, like a leather lotion, or something with glycerine rather that silicone. Silicone will also degrade the material over time, as engine bay dressings with silicone will eat through the rubber hoses after prolonged use.