1. I do the underside from the ground using a long-handled soft brush. Nest, I do the bottom half of the top side from the ground using the same brush. Finally, I climb up on the roof and do the upper half of the top side with the same brush.
2. I use to use a solution of Dawn dish soap and a bunch of bleach. Brush in on, scrub it in, then rinse it off. That method ended up making the vinyl awning very brittle, causing the vinyl to crack & flake off. It also ruined the stitching at the seams. I ended up having to replace the awning fabric last spring (after 7 years), and haven't needed to clean the new fabric yet. I would suggest a cleaner made specifically for vinyl awnings that both cleans and conditions. I have also read in another post (here) that the Dawn & bleach method is OK if you do a follow-up cleaning with
just Dawn and water to wash off the bleach. Then rinse that off and let it air dry before rolling it up. That's sure less expensive than the commercial awning cleaners. Not sure what I'll use when I have to clean it this fall.