I do wear shoes inside. As a kid, I always hated going to someone's house that made you kick them off at the door. To me it's just as bad to have feet sweat in your rug as the shoe itself, unless it's covered with mud or dog shit or something that is. Sometimes I take them off later if they hurt my feet, but I never, never take them off because of the house or the rug.(unless they're covered with mud or dog shit or something)