I have used Greased Lightning for years and it works great on the awning and black streaks. I buy a 5 gallon container at Lowes once a year for 27 bucks and use it for the rv and the house. For the rv I use a 1 gallon pump sprayer....I can wash the entire rv and awning with just over a gallon. I use a soft car wash brush on a long pole. After the awning is dry I treat with Armor All once a year....makes cleaning easier and keeps the vinyl soft