I personally have been there and tried it, and just dont enjoy it. Obviously some people of the old school (ditch will be along soon lol) think they are completly unnessesary. I know a few folk who work without them, including my dad who had been ferreting for a good 20 years and never lost a ferret, he waited alot though lol and they get along fine without them, fair enough.
As I said, I have tried it but just dont find it enjoyable. I dont subscibe to this rubbish about 'anyone who works a ferret without a collar is a cock' as some people say, its their way they can do what they want.