I use an extended handled soft bristled brush and dip it into a bucket of water with soap to wash and then rinse with a water nozzle attached to a garden hose.
For soap I use Chemical Guys Citrus Wash and Gloss - the dirt/grime just roll off and it air dries to a nice shine.
Also available at auto stores, WalMart and other big box stores.
2012 Fun Finder XT 276 Toy Hauler & Harley Davidson Ultra Classic with Condor wheel chock
2014 Dodge Ram 2500 AT 4X4 Crew Cab 6.4 L Hemi, 373 gears, tow package, Rambox option, Revolver X2 tonneau cover, Equal-I-zer anti-sway hitch.