Zapper.... good ideas.
When we return home with the Dust Clad Trailer and Tow Vehicle the Blue Beacon Truck Wash is open 24 hours. For $41.50 they have six or more guys with high powered wands to take weeks of dust, bug kill and cow dung off the Airstream.
No water leaks. We had a big 'cloud burst in Montana' with semi melted hail and heavy rain as we were coming out of Yellowstone Park on the last trip. No water in the trailer, but not enough to give us a Soft Water Washing, either.
(NO dents as the hail were reduced to large slush balls.)
Nancy wipes down the interior of the Airstream once camp is set and at home. A fine dust, which is expected. The dust in the rear window collects much like the fine dust in the outside Refrigerator compartment. It 'binds' together and you need to actually rub it and break up this stuff before the vacuum will catch it. This is a fine dust.
Leave Clean and organized, Return, Clean Up the Chaos... and Leave Clean on the next trip. Dirt, Dung and BUG gut on the front of the Airstream are a record of our travels. Crickets this year... Birds come to the campsite for the Buffet!
After 14 years of towing our Airstreams, the 2006 had fender wells that vacuumed dust off the roads. Airstream Jackson Center found the cause, trimmed the fender wells and sealed the majority of the problem. Dust collected inside, onto the interior floor.
The 2014 was 'nearly dust proof' from the eight years with the 23 foot Safari, experience.
Does it affect our lives? No. But if things like loose screws, popped rivets and dust accumulations can be minimized... I do not need to shower and after weeks Off the Grid, our Airstreams have been upgraded to handle future trips.
True Grit is an attitude... dust is not included.