IMO if you clean your bore very soon after cleaning the fouling doesn't have time to harden up and a nylon brush would be more then enough. But I use both bronze and nylon brushes.
Semi I don't know if I'd like that idea of epoxying a brush in a dowel. I have all my ramrod ends pinned because I have a tendency to use really tight patches. I can see that pulling out of the dowel and getting stuck in my bore.
Call me paranoid but having a brush stuck in a wet bore is no fun.Occasionally I was able to blow them out with my compressor. Other times I had to shoot them out. (That's why all my rod ends are now pinned!)