Hi there!
I am 40+4 and had a stretch and sweep this morning.
It was a bit uncomfortable, but not nearly as painful as I'd imagined. I tried really hard to relax (we've been to hypnobirthing sessions so I used the '3,2,1 relax' method). My mw was really good at informing me what she was about to do and why which I found helped me manage the discomfort.
It felt very much like a smear test, but went on longer (in good news it was less scratchy as they use a gloved-hand rather than a speculum).
There were three moments when it made me squirm a bit, and at one point I asked her to hold on for a second while I relaxed again, so don't be afraid to ask them to stop for a moment.
Since the s&s I've had a fair bit of bloody-mucusy-spotting so be ready with a panty liner/pad. And I generally feel a bit raw and sore...
I can't attest to whether it's worked yet, but it's nice to feel like I'm doing something other than waiting.
They give you a 'Bishops' score afterwards to rate the readiness of your cervix, my score was six, which I think is about the middle ground between not-ready and ready.
Good luck!!