The 17th February issue of Jinja Shinpō had an article about the dedication of a new toilet block at Taga Taisha, in Shiga Prefecture.
The previous toilets were built in the Shōwa thirties (between 1955 and 1964), and were difficult for the elderly and people with children to use. (That probably means that they were squat toilets, which were the Japanese standard sixty years ago, but are almost unknown now.) The rebuilding started last April, and the toilets were “reborn as facilities appropriate to the times”.
On the day of the dedication, the sacred space was set up in front of the toilets, and about twenty people attended the matsuri. They were purified, the kami called down, and the offerings presented. A norito was then read out, and the toilets purified. There is a photograph of a priest in his vestments waving the ōnusa sacred wand in the direction of the new toilet block.
Obviously, I am writing about this because it seems a bit odd. Indeed, having a whole article about the dedication ceremony for toilets is unusual.
On the other hand, it is absolutely normal for a jinja to hold this sort of ceremony when a new structure is completed within the precincts. Articles reporting this sort of event are common — on average, there is probably more than one per issue, although some issues have none. Further, toilets are important. Taga Taisha is a famous jinja, and gets about 1.7 million visitors every year. Having decent toilet facilities is essential. They have also made an agreement with the local council to make the toilets available in case of a disaster, something that is critical at those times.
Thus, the unusual thing here seems to be that the jinja built a freestanding toilet block as an independent project, rather than building another structure that included toilets. Looking at the picture, it is quite an impressive toilet block, as it should be with that volume of visitors.
The general lesson here is that you can, in principle, perform a Shinto matsuri for anything. In practice, if you are in Japan, your local priest is likely to be entirely willing to do a surprisingly wide range. If it is important to you, a priest will take the issue to your local kami, or to the kami of the appropriate location.
Normally, however, there would not be an article about it in the newspaper.