Stripping the amniotic mebrane away from the cervix to bring on labor.
Labor is a very complicated cooperation of many factors--fetal, maternal, hormonal, and mechanical. One thing alone won't necessarily push a woman into labor, including "stripping membranes." What your doctor is talking about is essentially just an aggressive pelvic exam in which he will feel around just inside your cervix where the membranes ("bag of water") are attached to its rim. By running an examining finger around the inside of your cervix, he can separate the amniotic sac from where it's stuck there. Theoretically, this will allow the bridging molecules that stick the membranes to the inside rim of the cervix to break--all at a molecular level, mind you--and so be released and then converted into prostaglandins, which are powerful stimulants of labor.
You would think that one time and wham! labor! But it doesn't actually work that faithfully after only one time. Usually it'll help irritate things just a bit so that an induction will "take" better. Repeated "strippings" may end up being performed before spontaneous labor develops, but then no one knows whether this is a coincidence or the result of finally enough stripping.
Obstetricians in private practice have come full circle in their thinking about stripping membranes. Once a favorite trick in training programs so that the patient would come back in labor when someone else was on call--a plot which didn't work--it fell into disfavor because of its meddling nature. Also, it was felt that such an invasive exam might introduce infection.
Then came HMOs, PPOs, managed care, and the uproar over C-Section rates.
Now it's once again done frequently so that spontaneous labor can be conjured up so as to have women have their babies at or just before term (39 weeks-40 weeks) before the baby gets any bigger, increasing the chances of C-Section. (The baby will grow by half a pound or more a week in the last month, so that the difference between a 39-week baby and a 42-week baby may involve up to 1 1/2 to 2 pounds more of baby to negotiate during labor.)
Stripping membranes is a favorite tactic on a diabetic woman to try to get her to deliver before she ends up carrying that humongous baby she's famous for. Also, women with Pregnancy Induced Hypertension (PIH--formerly called Toxemia) really could benefit with some meddling, since the cure for PIH is delivery. Vaginal Birth After Cesarean (VBAC) candidates may agree to the rationale for stripping membranes.
Yes, it's meddling. But so are antibiotics, ventilators, IVs, or anything else we've come up with since the witch doctor days. It's a practice decision made by your doctor which is part of the individualization of the care for you.