Im glad you recognize that though this "trick" may help you get out of a tough spot, it's not good and is only reinforcing a poor speaking behavior. I dont know where you are at with your stutter but if you could somehow just let yourself stutter on the word...since we are all stutterers after all, without the trick I think it'll be a lot better. And your listener will just hear you stutter which is fine and probably nicer to hear than random profanity.