I searched for ferret coping with only the ntl site coming back with the practice So I phoned my father who laughed down the phone at me. Having not touched a ferret for at least 15 years I questioned the laugher. My father says it's bad enough trying to get a ferret that doesn't want to go in it's cage. If you went near one with a needle and thread you'd need it yourself as the ferret is likely to put it's teeth through your thumb.
As for metal muzzles my uncle has some for walking the ferrets I'm told they go to the postbox and back, I didn't even know they could write