This is not really relevant to removing shoes, but for your information, I have now passed my PhD course.
In telling you that I have done a PhD, I am not making any claim to expertise on the subject of etiquette, health, environmental science or anything related to removing shoes in homes. My PhD is in historical theology and has nothing to do with the subject of this blog.
This blog is not a scholarly journal. It happens to be written by a person who has done a PhD, but it could just as easily have been written by an high school drop-out. This blog is my hobby. While I hope you will find the information useful and informative, it is also meant to be fun.