We have wood floors in the living areas, tiles in the bathrooms and carpets in the bedrooms.

DH and I generally wear shoes in the house. DDs generally take theirs off and either plod around in socks or bare feet.

The floor is often dirty. I go by the rule that germs build immunity They barely ever get sick.

Really, I just can't be bothered stressing about something that I don't see as a problem. So they might get dirty feet. Big deal, they have a bath most nights. If they have cold feet, they're old enough to tell me and/or put socks and slippers on.