It doesnt work for everyone, another one of those "if the baby and your body aren't ready it wont work" ways to induce(I think they are all like this though lol). I have tried it before, it did give me runs and I was miserable during it but I did have contractions sometime after that lasted about 6hrs then fizzled out. So it did something but didnt put me in actual labor.
Be careful with this method(& im sure someone mentioned it on here already) diarrhea causes dehydration so if you choose to try this drink plenty of fluids before, during & after.