I just read your post on another thread, indicating the ludicrous effort of a homosexual thinking he could "wine and dine" you into wanting to have sex with him. You referred to it as sexual orientation. How do you see it any different with your W? It sounds like her sexual orientation is not homosexual or bi-sexual, but simply non-sexual.
Is it really more rational to think you can (or should) do something to change her sexual orientation of "not liking it" into "liking it," when you could more easily (since YOU would be changing YOU) change your sexual orientation from "liking it" into "not liking it"? (No, I'm not saying it would be easy, it's just always easier to change ourselves than to try to change someone else.)
If you could take a pill to kill your sex drive, would you?