Quoting Squeaky McGee:" You drank motor oil? Yuck! You can't jump start natural labor. Natural implies that it happened on it's own. You're getting close. Hang in there."
But this. You don't have much longer, OP. And you don't want to be induced. If will most likely make labor more painful, and there is a whole slew of complications that could arise.
You can go from a 1 to full-blown labor in hours.
And you probably don't want to try drinking castor
oil again. It could cause your baby to pass meconium, and believe me, that is very scary. And not something you want to happen because of a choice you made.