We use a very weak solution of water and car-wash concentrate.
We make sure we rinse the AS of completely BEFORE we wash to remove as much loose junk as possible before we wash - with as much pressure as the hose gives us,
I use one of those ultra-soft brush heads on an adjustable aluminum pole for washing.
I make sure to brush in the direction of the 'grain' that is in the aluminum to minimize any visible scratches.
We rinse completely and then apply Walbernize - once in the spring and once in the fall.
For washings in between these two applications, I use a weak solution of car-wash concentrate with was.
So far, so good.
Windex on the windows, silicone spray on all the hinges, white lithium grease on the stabilizing jacks and step mechanism (and inside the ball receiver on the tongue) and every once in a while some plumbers silicone on the rubber window seals. Graphite in the locks and she's ready to go!
We use this stuff
Protect All Shine Plus Household & Solid Surface Cleaner, Polish, Wax & Treatment on the cabinetry, counter tops and the non-aluminum walls inside...it's great stuff - we use it on the laminate counter tops at home too.