Welcome to the support! I have had only one fistual that was perianal. I had a seton in about
a year before it came out on its own.
Have you discussed antibiotic treatment with the surgeon? Before they tried the seton, they tried flagyl (metronidazole) whci was helping to heal things quickly until I suffered a side effect that a few folks had. They then tried Cipro which was not powerful enough to work like the flagyl did.
The seton was work to keep clean and be gentle, but I was so thankful for the limited intervention needed with it.
Keep up your efforts...it sounds like you are on the right path.