Review on 🏕️ RV Rubber Roof Treatment - 1 gallon - anti-static, dirt repelling, and UV protectant - Optimal Shielding for All Rubber Roofs 68128 by Larry Breeze

I've tried most of what's available for this job and this is the only one I can recommend. You should check the seal at least a couple of times per season and check the corners of your roof after EVERY tow as this is where most kinks occur. A portable washing machine with a 20° nozzle is best for cleaning, don't worry about chemicals and cleaning. This material is the final step. I apply by hand and wear rubber gloves. Just pour a little and distribute, it's very easy. (Don't forget the roof edges, which lead into the gutters.) It leaves a nice layer of protection and a reflective shine that no one else has. This really reduces buildup on the roof, meaning it's easier to clean and you'll have fewer black streaks.