Double balloon dialtion induction

Has anyone had this done or know of how it works?
My OB is doing a cervical check on Monday 23rd which of course I hope will be enough to get things started.
But if it doesn't then on Tuesday evening he will insert the double balloons to dilate the cervix and then break the membranes wednesday morning.
So far in my previous pgs I have been induced with either breaking the membranes and having a drip in or just by a simple prostaglandin gel cap.
But now he has read up and says that is all too dangerous after a previous c sec even though I have had a VBAC since.
So I am taking raspberry leaf tablets, inserting EPO and hoping all is ready for Monday.

I have tried googling but come up with very sophisticated lecture notes which are way too complicated and more of a statistical thing than how the insertion is done and how it actually works.
Any help would be appreciated.
Thanks
Jude