Rainman, to be honest this one i have not seen, but it has been tried in the past sacs sedi tried it, worked fairly good for a while and works a little better for constant chain cleaners like myself, but after say 800 to a thousand miles they tend to self unlock on you especially under stress.
Personaly I would rather put up with the chain tool, for the security of not haveing a chain at all without notice they tend to not give any warning, you know if they were that good shimano and others would have come out with their own version long ago.