Licensed psychologist and hypnotist Richard Nongard writes about "Erotic Hypnosis,
Hypnoporn, Fetish, and Other Unspeakable Topics" at http://www.hypnothoughts.com/forum/topic/show?id=716892%3ATopic%3A64567 –
worth the read . . . both for the points Richard makes and for the responses. 
Some of his points fall directly in resonance with my own views about building
an inclusive open community for hypnotists which is what I attempted at the
get-go with the Society of Experiential Trance – http://www.trancesociety.org – and the
variety of specializations and contexts hypnosis is used for (some of the specific SET trainings and specializations are for topics that no other formal hypnosis society offers, in fact, some such as entertainment hypnosis and erotic hypnosis are specifically banned by a few) as well as with the
Hypnosis Technique Exchange itself – http://groups.yahoo.com/group/HypnosisTechniqueExchange – as
long as folks are behaving Safe, Sane, and Consensually (that’s informed
consent) then they are free to behave as they wish . . . Christ and Crowley and the rest had it right when they promulgated ideas like "And Hurt None, Do What Thou Will" and similar sentiment . . . with an inclusive open
community we are more likely to see the sharing of responsible approaches to
lifestyle or just plain ol’ helping folks avoid pitfalls that others have
already seen and dealt with.  It’s not like there’s no one out there who are genuinely interested in the subject, far from it . . . the erotic and sexual hypnosis section of my blog – https://briandavidphillips.net/ – is definitely one of the top categories that people visit the beastie.  In any case, see Richard’s post for worthwhile
discussion . . . and . . . throw in your two-pence whether you agree with him or not.