It's time to plug the Rick Fielding Banjo Mute again. Rick & Dave Cutler designed these, had several prototypes before they felt it was "right". It installs in seconds and not only mutes the banjo but gives it a tone almost like a harp. I haven't tried other brands, but some big time pickers at the 'Cat have and have said that this is the best one they've seen. I tried the diaper (actually towel), I've tried wedging something under the tailpiece, this is far easier to use on a resonator type banjo and also mutes it better.

PM Rick for more information.