I had the same issue with the suture line breakdown. I kept it clean, with my partners help.
3 weeks after surgery it was still open and some granulated tissue was growing on top (normal healing), and my surgeon applied silver nitrate - which dissolves the granulated tissue, but leaves other tissue intact. Mine closed over completley about a week ago (6weeks after surgery). The surgeonsaid I could use silver nitrate a month after he did it the first time if required, but there was no need.
I was a bit worried about it at the time, but with regular rinsing after dilation it never got infected, and it has healed really well now.