I have a duster on a long handle, with a turn at the bottom so it looks like a hockey stick. The end is covered with lambswool and it was a good duster in its day. Now, bits of lambswool come off in the dust bunnies when I use it. I love it, because it's shaped so I can get under the piano and around the couch legs.
I took a close look at it with the intention of finding a way to fix it, but in the end I found a way to recreate it. I am going to remove what little lambswool is still on it, then tear strips from cotton rags and tie them onto the form. I'll spray them with Endust or something similar and it should work just fine.
I have a little wool yarn left from a knitting project that should work well, too.
But why stop there? You know those brushes they sell to clean the dryer vents? Make your own with a wire hanger and some short rag strips. Or make a brush for very narrow spaces - you know, the ones you can see but can't get to?
I have some after Christmas projects lined up!
P.S. I'm working on the patveretto.com idea. Thanks for your encouragement!