I would definately NOT recommend it. It can cause terrible gastric upsets. My OB told me her daughter-in-law recently took it and spent the whole night on the toilet. By the way, it didn't even work and she ended up being induced.
It is difficult the last few weeks. How far are you? If you want some natural ways of inducing talk to your OB (would only recommend AFTER 38 weeks, baby is then full-term). Try intercourse with your partner, eating spicy foods, walking alot, walking a few times up and down stairs......mind you if the baby is not ready to come, then none of these will work. Best of luck!
remember that whatever you ingest your baby will ingest too....that being said it is highly recommended you do not use caster oil to induce labor
im not sure how far preg you are but the best and safest way to get things going is to walk...
also remember a baby will come when they are ready....having a baby too early is not safe and as a mother of premature babies (i suffer from preterm labor issues) it is not easy leaving the hospital without your babies after delivering them