Keeping your RV's awning clean is important and will extend the lifetime of that needed sun cover.  Here is a simple solution to keep them working.

VINYL AWNINGS
1/4 cup of dish soap
1/4 cup of bleach
5 gallons of water

After the solution is well mixed in a bucket, scrub down the awning using a brush.  After the awning is soaped up well, roll the awning up with the soap still sudsy for 5 minutes.  Unroll and hose off.  Let it dry before storing.

ACRYLIC AWNINGS
Simply, hose it off and let dry. DO NOT scrub.  
Scrubbing could cause the water-retardant finish to be removed.