Muffler repair...let it leak!

[Mikea2769@aol.com]

Looking to avoid cat-back replacement of exhaust system on my (still) good  
running 87 5kcstq. At almost 320k miles I'm just milking it till something 
major  put's her to rest.
 
One of the mufflers (above axle) has spouted a good hole with surrounding  
deterioration, on a rounded surface that makes patching a very temporary fix.  
I've used screening and sheet metal along with the sealer but it doesn't last  
more than a few weeks-the pressure blows it out eventually-no surprise. So, 
what  if I stopped trying to contain the pressure?
 
I'm aware of potential health dangers that a leak could cause-we don't  need 
to discuss this issue.
 
I can live with the leak-just trying to keep it quiet. What I'm considering  
is wrapping the area of the muffler in some type of heat proof padding (?) to  
act as a sound deadener-the exhaust will then INTENTIONALLY seep  through it. 
Long hose clamps to hold it in place.
 
So my question is..anyone have suggestions on what type  of material might 
work? It would be subjected to high heat of coarse as  well as wet weather.
Some type of heat proof fiberglass? Stainless steel wool?
 
THANKS
 
 
Mike  Aiello
87 5kcstq, 316k miles, orig.  owner