kk - have only read op and a couple of your latest posts, so hope I'm not repeating stuff.
I was induced nearly 5 months ago, with my second dc. I was 40+5 when I went in, but my induction was due to gestational diabetes.
The hospital wouldn't let me leave their grounds once the induction had begun, and I think that this is pretty standard procedure. I don't expect that they could hold you against your will, but it would be a brave lady who tried to escape!
I went in on a Monday afternoon, and spent Mon/Tues/Wedns having pessaries that didn't work. I then had to wait until Thurs night to have my waters broken, as delivery was full. Breaking my waters was difficult, as I was only 2cm dilated and posterior, but it could be done. As a first timer, if the pessaries don't work at all for you, then breaking your waters won't actually be possible (because your cervix won't be open enough for them to get in).
I had my waters broken on Thurs night, but still didn't go into labour, so after 4 hours I asked to go back up to the ward for the night, rather than have the drip right away. This was seemingly an unusual request, but after checking with the registrar (who agreed, but wasn't described as 'happy about it'!) they agreed. So you can ask for a bit of a delay here if you want (once they break your waters you only have 24 hours rather than the 72 that you tend to get if they break naturally, because the risk of infection is increased by the method).
I had some contractions overnight, but really not enough, so the next morning I finally agreed to the drip. Drip started 9:25am (when I was 2-3cm), 4cm at examination at 11:25, and ds was born at 12:35!
If the pessaries don't work and they can't break your waters then they may offer the drip in the hope that the contractions dilate you quick enough, but if they don't then it will lead to an em cs.
If you don't want the drip at this point then the alternative is an elective cs.