Good question. Everywheres I've camped since buying my van has been full of endless dust. In one of his videos, Bob Wells talks about the evils of having carpet in an RV, as dirt gets tracked in continuously, especially by canine friends.
In my own situation, I've dealt with this in 5 ways (besides having no dog). 1. I have a carpet that's actually a 36"x72" doormat made of polypropylene and can be easily removed and washed. 2. By the entry side of the door mat, I have a strip of thick plastic sheeting, 18"x36", which can be easily swept clean. 3. on the initial step of the van, I have a piece of cloth, which takes most of the dust in the first place, and can be shaken out and also washed, and the step cleaned. 4. On entering the van, I also remove my shoes, so most of the dust never actually gets past #3 in the first place. 5. I also commonly put newspaper on #2 to keep that area even cleaner. A systems-level approach (obviously thought up by a retired engineer). The idea is to capture most of the dust at the outer levels so very little gets onto the inside carpet #1.
A lot of people I've noticed in the videos have a rug that goes on the "ground" near the door to their RVs to rub their shoes on to.