Fought that for years. was good until I put it up after camping in the rain and left it for one week. Was Never the same.
I used spray and cleaners and it got about 80 percent clean and even scrubbed it.
New camper has a awning cover and it is awesome.
2007 Chevy 2500HD 6L Auto 4WD
2015 Keystone Outback 5th Wheel
Wife and 2 great kids, Son-Army 45th
Yellow Lab