From my experience, provided your cervix is "ripe" enough (I hate that expression) an S&S is more likely to prevent a chemical induction as it can help things along a little.

I lost mu mucous plug within 24 hours of having amembrane sweep. I had already been booked in for induction and wasnt informed enough to know I could wait a bit longer (or I would have) but think that the S&S contributed significantly to me only needing 1 lot of gels put on, no drip etc.