What can I use to thin my cervix?

I am 37 weeks pregnant with my 2nd child, and I just recieved an ultrasound, and the baby is doing well, and is big enough, but the problem is I am MISERABLE. I want to have this baby, but I want to do the most natural way possible. I took castor oil with my first baby, but I was dilated already to a one. I am not dilated or anything yet. I want to get a kick start on having this baby. Castor oil, yes, did work the first time, but I hear it only works if you are dilated, then I heard from someone who heard from her doctor that castor oil does thin the cervix also. Since, I am not dilated, I do not want to take the castor oil, and **** all day and be in pain from having to many bowel movements. What should I do, is there any thing that I am able to do, or am I **** out of luck, and have to wait for this baby to really come on its own. PLEASE HELP ME!