I would look for a new muffler. The repair may hold for a while, but if the muffler has a hole that is from corrosion and not hitting a rock, it will soon just create new holes.
*Project Yeti* 99 JGC Limited 4.7 w/6.5" Rockkrawler LA & IRO A-arm, Goodyear MTR 35's on MB TKO's, 4.56 Yukon's, Iceland Offroad Bumper/Flares/Sliders, Protofab Rear Carrier, SuperChips, Uniden/Firestick, Flowmaster, Smittybilt 8k Synthetic Line Winch.
My Jeep is Organic - Undercoated in 100% all natural Utah Dirt --- Utah Jeep Crew #49 ~Will
2012 JeepForum GCOTY --- [URL=http://www.jeepforum.com/forum/f197/project-yeti-abominable-wj-1125665/]Project Yeti Build Thread[/URL]