I have an RV fistula and go to the CC (Dr. Hull). She told me - with absolutely no doubt - that my fistula will not heal on its own. Something to do with being extremely angled... She offered up several options, of which she honestly told me had very little chance of success, such as the LIFT, and the other usual fistula surgeries.
She made it sound as though the only way to rid myself of the fistula - and this wasn't even a 100% sure thing - was to have a pouch redo (or removal). Since I will not go through a redo, I am living with the fistula and seton and have been for 3+ years.
I am disappointed you're not getting more info from CC, and that they are not "insisting" on a seton in the meanwhile. You may want to think about trying another seton which could lessen your pain and prevent any abscessing. They are supposed to help with the healing process, as well. Is it possible that the first seton used was not of the most comfortable material? Mine is "rubber" looking (yellow), and there are 2 there for redundancy. I had it changed last year, and the new placement was uncomfortable for the first month or so, as I believe it was tied a bit tighter, but I've adapted to it and no longer feel it.
If you haven't seen Dr. Hull yet, I highly recommend her. She is VERY informative, very thorough, will not sugar coat anything, and will talk with you for as long as it takes to help you understand every option.
So sorry you're going through this.