Autoerotic asphyxiation was used as a plot device in an old X Files episode, and it also figured in the movie version of Rising Sun (I don't remember if it was in the book, as well). Newspaper accounts of Caradine's death have been very circumspect in their reporting. Suicide by hanging is all I'd seen before this strand appeared.

Regarding comments above about the history of pornography, there are lots of pornographic (i.e. sexually explicit) wall paintings from Pompeii, usually assumed to be decorations in brothels. Well- and extensivly illustrated in Jean-Claude Marcade's 1965 book, Roma Amor. Companion volume of classical Greek erotica by the same author is titled Eros Kalos. Sexually explicit images in religious context were part of these cultures, as well, but I think it is fair to characterize most of what Marcade illustrates as good ol' secular encouragement rather than cult.