I can safely say I've never had to sit in a house for 35 minutes listening to Muslims extol the virtues of their faith (had to do that a while back with some Mormons. My sister's fiance answered the door and they were there and they didn't really know how to properly turn them away, so they invited them in
perhaps she could have told them to go away and closed the door? probably a tad safer than letting random people in to have a chat...