We get a lot of dust in ours as well. But then it's parked in a campground with a dirt and gravel road. We find that doormats (inside and out) help alot with tracking dust IN the trailer. I just sweep and sweep...
Oh and it doesn't help that our electric blanket lints all over the place (despite numerous washings)... just adds to the sweeping and the dust...
Someone I know keeps a HEPA filter in his 'stream... maybe that will help?
(Eau Claire, WI... drove through there in Sept on the way to visit family in Spooner.)
/Lois