You'd be surprised how many don't then. Take apart your stock pipe on your RR, it's just baffling and metal plates as are the vast majority of OEM pipes. Steel wool is hard to deal with at the factory and will degrade with time, baffling doesn't.
Actually, my other Honda also has stainless steel wool in the OE muffler. If stainless steel wool degrades over time I wonder why so many vintage,decades old Honda's with silky smooth OE exhaust still have the original wool from the factory in them?
All I can say is that I have a great deal of experience re-packing my Yoshi with all sorts of crap from the market place. In the end, the only thing that would not blow out or degrade was stainless steel wool...
I was put on to it from riders with decades of riding under their belt. They were all very familiar with the story and kindly turned me onto it. I was back then that I started looking at vintage bikes with OE pipes on them that had never been touched and still sounded great. What was in each and every one of them right from the factory? Stainless steel wool.
The real crucible is once you put 10 or 20,000 k on it. At that point the men get separated from the boys and all the aftermarket packing has long since blown out. They all sound good once re-packed but it's mileage and age that will reveal which packing really works.
If you think about it, the OP was asking about re-packing his Yoshi. If it were done correctly, it would never need re-packing. My Yoshi was exactly the same. It was cured with stainless steel wool. Ceramic fiber did not cut it. Aftermarket 'pillows' didn't cut it. They all blew out over time. I found that the only thing that won't degrade over time or blow out is well-packed stainless steel wool.
2006 CBR 600 RR w/52,000 K
-Valve Clearances (Loose Side)
-New Starter Brushes
-New Thermostat & Flush
-New OE Front & Rear Pads & Caliper Overhaul
-OE Air Filter
-Chain & Sprockets (15/45 & 14/45)
-Front Forks & Seals
-OE Clutch & Basket
-Gear Position Indicator
-New Headlight Assembly
-New Instrument Cluster Case
-Rear Shock Overhaul
-Metzeler Sportec M7 RR Tires
Powder Coat rims/Wheel & Steering Bearings