Quoting Nicole Jean Sanderson:" I am thinking of trying castor oil, my grandfather who has cancer really wants me to have my daughter ... [snip!] ... to see if they can scrap my membrane. if you have any tips that'd be great! i really want to have her on my grandpa's birthday!"
No No No No
There are plenty of reasons why you shouldn't do something like this.
Why don't you ask your Dr to strip your membranes? That can push labor along if your body is ready.
Basically, if your body isn't ready to go into labor nothing you try at home is going to work. The only sure way to have a baby on a certain day is a c-section. even inductions don't work all the time.