Dirty shoes coming into your RV make for a dirty carpet and extra cleaning. One really handy item to have is an RV entry shoe brush. No, not the hand held kind you polish shoes with, but the stationary kind that you scrape your shoes on.
There are all kinds of shoebrushes. Some are shaped like animals with bristles sticking up for fur. Every time you come into the RV, just brush the bottoms and sides of your shoes on your spiny little friend.
We were shopping in Harbor Freight and found an a great shoe brush. I found ours at their store, but I could not find it at their online store. Ours is not decorative or fancy and it is not cute at all. It's feature is that is does the sides and bottom of your shoe at the same time. They have a similar 3 sided brush at the link I gave you above.
We live at the beach and often camp at the beach. Salty sand sticks to everything and becomes a part of your carpet. Having a shoe brush at the RV entrance is a great help in keeping the RV cleaner for longer.
Not only does you RV get dirty, but you also get a lot of dirt and sand in your car or truck. It's amazing how much stuff, even sand stays stuck in the tread of modern athletic shoes. We keep a couple hand help scrub brushes in each of our vehicles. One on each side in the door pockets. When we get in the car after a walk on the beach, we brush the bottoms and sides of our shoes. Not only does this keep the car cleaner, but it also keeps our home cleaner. That sand just seems to stay in the shoe tread forever and drops off in the car but also at home long after we left the beach.