Unfortunately I'm in the same boat with you guys. I have tried sexy clothes, she tries them on once and to the bottom of the drawer they go. Videos and toys didn't work either, a 2 years ago I gave up and stopped asking for it to see if she ever would and she never did.
I recently decided to start playing in the hobby as an alternative, really no other choice unless I want an unenthusiastic Cowgirl action from now on.