I'll second Bongshang's concern that muting a banjo can result in your unknowingly playing harder to compensate. Not only is there a danger of causing muscle problems, when you take the mute off and play with the same force, the volume is deafening!
This is a real issue for most of us here in the UK, where most people live in high density housing. I'm lucky to own a superb pro quality banjo, and it breaks my heart to lose the tone and volume. My solution was to buy a used Nechville Meteor many years ago. With this I can play without disturbing my wife, dog and neighbours. I find that using a small practice amp and headphones, I can get an acceptably banjo like sound and volume without changing my right hand attack. I realise that this is an expensive solution, but it certainly works for me.
I took an old electric guitar and strung it like a banjo. Probably not optimal as the feel is different but at least it is very quiet and I can practice whenever I want.
Flipping the blades makes a dandy shop clamp. A shop trick from the '30's model airplane builders.
'UK Shackleton Banjos' 59 min