We have a black spot on the inside of our pop-up that appears to be grease based. We've tried Dawn, bleach, and some other soaps and nothing is getting it off. Any suggestions on another cleaner to try? Also, when we were camping this weekend my wife reached up to knock some of the leaves off the vinyl above our bed and when she did that, water drops fell on me. Is there something I need to spray on the vinyl to keep water from soaking through the vinyl? We have plans to clean and waterproof the canvas this week, so I'd like to take care of the vinyl at the same time if possible.