We were looking at our awning that has a little mildew. Someone at a campground told me that he uses a 50% mixture of Simple Green in a spray bottle. He then roles the awning up for 30 minutes. After ...
I use "awesome" from the Dollar Tree. You can get it in normal strength or you can buy the straight stuff and mix it yourself. I have both so I can use something stronger if needed. This stuff is, well - awesome. :B
I soak the awning with a liberal amount that I spray on and then roll her up, 15-30 minutes later a little scrubbing may be necessary and then rinse and good to go.