During my ongoing mission trip to Japan, I spent four days in a log cabin whcih had been built in the Forties. Although we all took our shoes at the door, the insulation was poor and the place was full of dust.
All that dust was not fun. My slippers were new, but they soon looked like I had been wearing them for years. Of course this dust is the same stuff your shoes pick up. How much worse would the house been had we kept our shoes on?
To reduce dust in your house, you should seriously consider instituting a shoes-off policy.