Yes,this is a fairly common approach. When you have a sinus tract, it is similar to a fistula. The main difference is that the sinus does not connect. It is a "blind" end. Trying to remove it basically winds up being a pouch reconstruction, with all the risks associated with it. But, if it were me, I'd look into less invasive approaches before committing to surgery.
Being like a fistula, a sinus also has an epithelial tissue lining, like skin, so it sort of is like a new organ. You could think of it sort of like an appendix, but not "dangling" like the appendix. This lining is what makes it stubborn to healing. The body sees it as normal organ tissue, not something that needs to heal. It is a problem because small bits of stool get trapped in there, causing infection. In your case, it has been very stubborn, because it appears that most of these small leaks heal within six months. After that, you assume it is there to stay.
The procedure you are talking about basically opens the sinus to make it part of the pouch. It is effective most of the time and avoids the big procedure of reconstruction. You could go ahead with the takedown an see how it goes, but your surgeon probably would not go for that.
Dr. Shen at the Cleveland Clinic does this via endoscopy and without an open incision or laparoscopy, and calls it a "needle-knife" procedure. He uses endoscopic tools over several procedures to gradually open the sinus to the pouch. You may want to inquire about it.
http://www.ncbi.nlm.nih.gov/pubmed/22390150But, I don't believe he also incorporates tacking the pouch to the posterior wall. That procedure I have heard of being used when there is a problem with the pouch collapsing or twisting, causing emptying problems.
Jan