Off topic as it has gone, but O.K as far as the Title goes, I've just got to tell you the story of what happened with a well known Foot in the Door "brother" when I was kid in the 1950's. Bro. F.I.D from now on.
My dad and I were knocking on a door a few door up from Bro. F.I.D, on a row of 200 year old cottages that had front doors right on the pavement, he seemed to have a good conversation going, he had his body half inside the little cottage, his Bible out and open, and must have said something outrageous as all of a sudden the guy inside gave him a hard shove, and slammed the door, Bro F.I.D fell backwards on to the pavement, a surprised look on his face, and dad burst out laughing.
What made dad and me laugh even more was, Bro F.I.D had placed his briefcase inside the cottage, and had to knock on the door to get it back, the guy threw it at him ! I thought all this was hilarious, being about 7 at the time, but was bit surprised that dad did, but he explained to me that he had warned Bro FID about putting his foot in the door a few days before !