Every issue of Jinja Shinpō includes a short column written by someone at Jingū, and the December 12th instalment was about the gravel on the paths.
Look, they have to produce one of these every week. Cut them some slack.
Actually, it did have a very interesting part. Gravel gets caught in the tread of shoes, or even gets inside the shoe itself. That’s just the nature of the stuff. It means that people often take some of the gravel home with them, without even noticing.
The interesting part is that Jingū often gets letters from people saying that they had accidentally taken gravel home with them — and returning it, carefully wrapped in white paper.
This is not, I hasten to say, something that Jingū tells people to do. However, the idea that things found within the precincts of a jinja, especially Jingū, are sacred, and should not be removed, is one that is found in other parts of Shinto as well. It is interesting to see how strong that belief still is in some people.