You can try two different things depending on your preferences.
1) A homemade mix of bleach / vinegar (33/33 ish) with warm or hot water as last 33%. Soak and scrub some. Works ok, I found this on some other RV forum but don't have a link.
2) LA Totally Awesome (dollar general approx $3 for half gallon). Don't dilute, use spray bottle on spots soak and scrub. Works better than #1.
I had some bad spots due to pine needles stuck in roller track which leached into canvas.
As far as cleaning many products will do the job,on occasion we have used Awesome found in $1.00 stores.
More important is how Many times a year do you have to clean it. This is the secret.
We had a trailer 12 years,in the sun 24/7, But when we finished cleaning it we Sprayed it,top and bottom with chlorine free bleach. Found in most grocery stores. It does not eat the stitching or seams,keeps the mold off and protects the color. Have fun!
Totally Awesome is what we use. Well it's totally awesome! (Sorry, had to do that)
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Chris & Donna
2014 Voltage Epic 3990, 600AH LifeBlue, 1895W Solar, 3K Magnum w/AGS, 3X Micro-Air ES
2018 RAM 3500 Laramie Sport Crew Cab 6.7 Cummins, AISIN 4X4 DRW 4.10 Long Bed Dually
We use Outdoor bleach, vinegar, & water. Spray the bottom side and top side and roll the awning in and let it sit for an hour or so. Then roll it back out and hose it down. Any "rough' spots we spray again and scrub with a bristle brush. Do this 3-4 times a year and she stays pretty darn clean.
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Jeff & Sheila
2016 Aerolite 213RBSL
2013 F150 3.5 Ecoboost Tow Package
We use Outdoor bleach, vinegar, & water. Spray the bottom side and top side and roll the awning in and let it sit for an hour or so. Then roll it back out and hose it down. Any "rough' spots we spray again and scrub with a bristle brush. Do this 3-4 times a year and she stays pretty darn clean.
I use 30 second outdoor cleaner. I apply it with a brush. Wear clothes you don't mind if they get bleach stained.
If you have a “Dollar General” store nearby go pick up some Awesome spray. It works just like the name replies and is very inexpensive. They have spray bottles and gallon jugs as well.
It appears that totally awesome cleaner is suggested by many. I do have a local store that has it in stock. Although I have further questions on its use. For those using it, do you spray it on full strength or dilute it? If you use it full strength, does it harm the aluminum siding on RVs? Thanks in advance.
A couple weekends ago me and the Boss bought the gallon jug and used about half to a gallon of water and then brushed it on. Let it set in while doing the other then just rinsed off with a power washer. Looks Awesome!
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Chris & Donna
2014 Voltage Epic 3990, 600AH LifeBlue, 1895W Solar, 3K Magnum w/AGS, 3X Micro-Air ES
2018 RAM 3500 Laramie Sport Crew Cab 6.7 Cummins, AISIN 4X4 DRW 4.10 Long Bed Dually
Stubborn stains you can use it full strength. Watch the dirt and grease just drip off. Lighter cleaning you can dilute it. Never had any problem with it harming surfaces I’ve cleaned. I use it all over the house. It’s a Great Degreaser!