On the subject of the dangers of a healing service disguised as faith healing, I again think you are projecting your own viewpoint on to others. I don't feel there is nearly as much danger from success as you do. Why? Because the vast majority will identify modern medicine as the source of the healing rather then the faith healing.
You say that even in America successful faith healing would attract attention, but that is simply not true. I have heard first hand accounts of dozens of faith healings in America, and have personally witnessed three. One of which was in a major city. In none of these instances has there ever been any significant interest outside of the immediate family and friends of the people affected. Why? Because people who believe nod their heads and say it must have been God. People who don't believe shake their heads and attribute the healing to modern medicine instead. Every once in a while CBS or Discovery does a documentary on faith healing and they always end with an inconclusive note (primarily because they don't want to offend the 80% of the audience that believes in them).
Nor do I think "cult" is the first thing people would leap to. First of all, we do not intend to advertise that our healers are associated with the boarding house. How would people connect the two? Nor is it likely that we would get blamed for the water contamination, since the cause of the contamination was already reported.
You assert again that modern, financially secure people do not generally accept faith healing. This is factually false. As I previously linked, about 80% of Americans believe in miracles and prayers as ways to heal. Now this does not mean that Japan is the same, as the stats I was able to find on Japan are much less conclusive, but clearly neither modernity nor monetary stability lead to rejecting faith healing.
You assert that faith healing is "really really really weird in Japan." Do you have any direct knowledge to back that assessment up? I mean, do you live in Japan? I don't live in Japan, so my knowledge is of course second hand, but my impression of Japan is that while the Japanese do not formally adopt a religion, a majority clearly follow Shinto traditions. Traditions that include ritual cleansing of impurities and yes, faith healings.
It may seem strange to you, but my experience has been that people can easily hold both the position of rejecting religion, and also participating in religious rituals. Thus you get 72% of Japanese not believing in religion, and yet 80% of them participate in Shinto rituals.
This article notes that over 213 million Japanese are registered with religious institutions, which is roughly double the population of Japan. It specifically mentions that asking a Japanese person "What is your religion?" is not likely to get a meaningful answer since the question is not particularly meaningful to the traditional Japanese way of thinking about religion.
This article introduces Shinto, and identifies Shrine Shinto, Sect Shinto, and Folk Shinto as branches of Shinto. Sect and Folk Shinto both have faith healing activities, and Shrine Shinto has
cleansing rituals. Shrine Shinto is by far the most prevalent of Shintoism in Japan, but from what I read, these other sects and folk traditions are
not treated as Aum equivalents.
Similar articles can be found:
Here,
here, and
here. As well as several others I did not bother to link.
Tenri-kyo is specifically called out as a faith healing
Shinto tradition, with over 2.5 million members.
If I were to compare it to Christianity, Shrine Shinto is similar in position to mainline Protestants and Catholicism, while the Sect and Folk Shinto is similar to Pentecostals, Mormons, and other charismatic churches that practice faith healings. Aum is analogous to Jonestown or David Koresh. Thus claiming that if we participate in faith healings we will be equated to Aum is not an accurate assessment from what I can tell. Rather we would probably be equated with Folk Shinto, which while not commonly practiced, is familiar enough that people aren't going to be freaked out about it.
In general, it appears to me that Japan, while rather secular, is also very tolerant of religion and religious rituals. I see no evidence of the hostility you suggest we would encounter. Are you sure you aren't projecting your own views on to the Japanese?
If you have some personal knowledge of Japanese attitudes I'd be more open to being persuaded, but all the secondary sources I can find suggest that the hostility you think we would face is extremely unlikely. Of course, I don't have direct knowledge either. Maybe we should ask one of the SV members who is Japanese such as
@LordPanther14 if they have any insights they would like to share on the matter.