You may not like this, but YOU are possibly the biggest source of dust in your Airstream. Dead skin cells.
Yep, dead skin cells. In such a small area there is no place else for them to go. Between showering, changing and drying your hair you create a lot of dead skin cells. Then there's the normal shedding inside your clothing and abrading against the sheets (NOW no comments about THAT!

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Of course the amount of dirt you tromp in because you don't walk on sidewalk prior to entering your door adds to the mess.
So what's the solution? Well in a small trailer only a very small vaccuum cleaner is practical. Frankly a broom and and some good microfiber dusting rags are faster and do a better job. I've tried dusting sprays and pledge - which I do like to keep water marks off the formica round the sink, but most of the time I just moisten the microfiber rag. I generally go over all the horizontal surfaces daily, and do a quick sweepdown at least two to three times a week. I find that if I don't wipe down the bare aluminum interior at least once every six weeks, it does get a film that is probably mostly breath and cooking moisture.
I have an uncarpeted A/S, and have two rugs that run down the length to keep my feet warm. I find it helps a lot to take those outside and whack them over a picnic table from time to time. I also use a very small shark vacuum on them about once a week or so. I do replace the rugs rather than trying to clean them.
Short of changing clothing outside of the Airstream and always using a bath house to shower, you're going to just have to keep up with it. Of course if you've got dry skin, a good lotion or shower gel might help.
Paula
PS: One thing I got tired of RIGHT away was a down comforter. I even tossed my down pillows and went to a high end down substitute. Those tiny little featherlets drove me crazy.