When we had our pop-up we just used a very mild bleach water solution and a scrubbie of some kind. Yes, it took time, but we always kept the mold at bay. After cleaning, we made sure it was always rinsed well, and dried. We treated the canvas with water repellant (like for tents) twice. We owned the PUP for 6 years.
You might try Mr. Clean Magic Eraser. Make it wet, but not dripping, then just wipe once, let stand for about 10 seconds and wipe it again the second time. This works magnificant for our awning. Yes, it's a little work, but Mr. Clean also has a mold retardant in it that prevents mold from coming back. I clean the awning 1 time a year (in the spring) and when I put the camper up in the fall, it's still clean. Over the winter, it get's black and dirty. Never did figure out how that happens with a rolled up awning. But in the Spring, one cleaning with Mr. Clean Magic Eraser and it's good to go again. We've never sprayed the awning on the TT.