Vinyl Roof Cleaner

We talking a big 5ver here, right?

i seriously doubt your roof covering is vinyl. In fact I’d bet a large sum it is not. 
However, it is likely EPDM or TPO. And there are products marketed as roof cleaner for those surfaces. But they are not pure magic like late night infomercials. 
Doubt there’s anything that won’t require some scrubbing or a pressure washer if the roof is dirty from being stored/used uncovered anywhere short of dry and lots of sunlight for long periods of time.