Castor oil for labor induction with previous c-section

I was having those irregular bh contractions with period like cramps since yesterday and had my bloody show late that night. But seems like no progress now. I am 39+3. 2 cm dilated and baby did't fully engaged yet. I had my DD with c-section 17 months ago. I am considering castor oil for labor induction but since i hope i could have a VBAC i'm afraid it will complicate my chance. Any one out there tried it before and progressed safely?