They say comet and spic and span is OK. They say stay away from any cleaner that has petroleum distillates and citrus
From RV site
Regardless of the type of rubber roof you have, NEVER use any cleaners or conditioners that contain petroleum solvents, harsh abrasives or citrus ingredients. These types of cleaners can cause permanent damage to rubber and vinyl surface. Rubber roofs already have built-in ozone and UV protectors, and cleaning a rubber roof is quite simple. You can use household cleaners like Comet and Spic And Span or Dawn dishwashing liquid for most routine cleaning needs