You don't wipe your dogs' feet off if they're dirty?

If they're notably gross, yes. But not if they were just outside and came in normal. Which is my point. If someone's shoes are notably gross, that's also a different story.

Ha! My 65 pound dog still thinks she's a puppy (and she's 8 years old, dammit), the idea of trying to slow her down long enough to clean her feet just makes me smile. The blasts past me at a hundred miles an hour and then tears up the stairs so fast that I think one of these days she may actually tear the carpet.

And anyway, have you ever tried to get a dog's paws clean? Like, meaningfully clean?

I have Roombas and I hire a housecleaner once a week. Our house is actually pretty clean in spite of the silly dog.

Those are strongly correlated rather than independent variables though - see my sibling comment :) [1]

1: https://news.ycombinator.com/item?id=36424356