If this is true, then this form of specialised nosebleed might have been depicted in art for quite awhile. But of that I have no knowledge.
An interesting thing, I just realised, is that if this is the true history of the sexually ritualistic nosebleed, then
(a) women had no need to develop such “skills”, and
(b) homosexual men also had no such need.
Thus much of the anime and manga today—especially in the boys’ love scene—are not true to the real history! :P (Male homosexual acts were in these times—again, in the upper classes—something considered pure and good, as females were “worth” less and not something you might not have easy “access” to when you felt certain urges.)"