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 and all manner of other objectionable things.
It is not reasonable to assume that your guests have cleaner shoes than your children or your husband.