Not in your DDC, but Your body will go into labor when you and the baby are ready. Even after having pit four times, your body will do what it's meant to do. It was just never given a chance before.
If I were you I wouldn't do any more "natural" induction techniques unless you're after 43 weeks. Even then, I personally wouldn't, but I know some people's comfort level is less than mine. The reason I say don't do anymore is I think that "natural" induction as well as non-natural - like pit, etc. techniques can possibly start a start and stop labor or begin a long labor when your body or baby isn't ready.
Maybe you had a 24 hr labor with pitocin because your body or baby wasn't ready yet? If doctors and you let your body and baby work on its own, then you may end up having a short labor. I have heard several ladies who said that they had their shortest labors - with the baby that had stayed in the longest. I think this is because it gives your body and baby more time to get in the right position, efface, etc.