i once read a book (fiction stories) about a chinese doctor type who "treated" ladies with all manner of things in this way.
it generally involved some kind if leather dildo affair that was filled with different kinds of postions and herbs etc, then inflated with some oil i think it was, and the effects would multiply and escalate the "patient" into cataclysmic orgasms.
i don't remember the name of the book, but i will have a think.