I've never heard of such a thing. I just had all my kids delivered when they were ready to come out. So I read up on castor oil. It does have some risks but can trigger some labor contractions by stimulating the intestines. It may work, it may not. You just never know how your body is going to react. Yes, being humongous pregnant is uncomfortable but it doesn't last forever. If this is your first baby, you're in for a surprise. You'll wish you could stuff her/him back up there again after a couple weeks. LOL
Really, good luck and congrats. Kids are a lot of work and turn your life upside down but they are also quite fantastic.
btw I am not 35 weeks lol after the ultrasound I got yesterday dr has me at 38 weeks so don't freak out on me lol dr said to try whatever to get me dilated lol