I think it's another of those inducement methods that only work if you're really close anyway. That said, it didn't work for my 1st baby, but did work for my 4th. I got up from a nap and tried it; got some good contractions and was able to keep them going somewhat throughout the day until my body took over later that night.
With baby #5, I had a very strange labor. I was pretty much walking around at a 7 (I asked to be checked after 2 days) with no regular labor pattern established. Nipple stimulation kept contractions going for a couple of hours, but still never really kicked things in to high gear.
This is baby #6, and I have tried MULTIPLE times to kick-start things, but like a previous poster, I only get some really strong B-H, but nothing that takes on a life of its own. Guess she's just not ready.
All I do is rub my hand/fingers back-and-forth--nothing really mean or strenuous. It begins to work after 7-8 minutes, usually.
Korrie, with baby #6 at 40+3