I had sweeps with both of mine.
With DS1, I had my first at 40+4. The midwife commented that my cervix wasn't favourable and she couldn't really do it properly. It didn't hurt and I had no cramping afterwards. I went back again at 41 weeks and she managed to do it properly that time. I had no cramping, spotting or anything for the rest of the day, even after walking about 6 miles so assumed it hadn't worked, but then contractions started at 1am the following morning. I had a thirteen hour labour and uncomplicated birth.
With DS2, I had a sweep on my due date. My midwife said I was already 4cm but did the sweep anyway and my waters went as she took her hand out. She said it's pretty much impossible to break waters just with her fingers so they just have been about to go anyway, or even have already gone and her dislodging the babies head allowed the fluid to gush out. Contractions started 1-2 hours later and he was born another 3 hours later.
At the time of having a sweep, I found it to be horrendously painful, probably more intense than any part of labour for me. The midwife commenting that she had her fingers behind the baby's ear didn't really help! However, if you can breath through it (or just hold your breath and squeeze on something hard) for the 30 seconds max that it takes, it's all done and I personably didn't notice any particular discomfort following.
It may or may not have helped with my first, and certainly kick started things with my second, and did absolutely nothing at all when my body just wasn't ready, so I'd take a sweep again if I was nearing induction deadline (or section deadline in your case). However, if everything is well and I go overdue with this one, I'm going to try to delay a first sweep until about 5 days past due date, rather than due date or earlier, to give a bit more time for it to happen naturally. If I hadn't had the sweep with number 2, I don't think it would have been long before he arrived anyway.
