There's better stuff out there now. The local shops sell Yosh "pillows" of repacking matierial. I redid my own Muzzy's even through they were close to new. There isn't much material in the stock Muzzy's to start with and that's where a lot of the noise comes from.
Flow, you've got the twin Muzzy's so you'll need to buy 3 pillows of this new material. What I did with my cans was remove the back end (screws) and ram pack the remaining glass to the forward end. Don't pack it solid but do pack it so it's about the firmness of medium foam rubber. Then cut open the pillows of Yosh repacking and feed and tamp in one and a half packs per can. Pack it tight enough that it feels like a medium foam rubber again. You want it firm but not solid. This may mean that you can't fit in the whole pack and a half of new wool but match the foamy feeling rather than ramming it in too hard. If there's some left over so be it. Be sure that you have the last of it sticking up a bit so as you replace the end cap there's some packing filling the cap hollow.