My girl is lazy about eating PK too. I've been feeding live since they went back on feed this year, but whenever I have needed to kill a refusal (due to lack of housing) she takes them without even constricting. It's kinda funny. I dangle it and she grabs its nose and starts swallowing.
I'm with cordell though, I started breeding so I wouldn't have to feed FT anymore. I don't like taking instinct away from such already lazy animals. I would only feed PK to a snake who was afraid of live or previously eating PK/FT (and I'd probably switch them). Pfft, I even feel bad about not allowing them breed. I guess I'm just sensitive LOL.