I sometimes read blogs where the writer says 'I have a shoes-off policy in my home.' Then in the next paragraph, she states 'I would never ask visitors to remove their shoes.'
I am sorry, but if you normally let visitors come in your home with their shoes on you do not have a shoes-off policy. You have a shoes-on policy. You permit shoes to be worn in your home that have been on public toilet floors, which have walked on weed-killer saturated drives and which have walked on lead paint.
It is not reasonable to assume that your guests have cleaner shoes than your children or your husband.