I think that self regulated corridors with only air-to-air frequencies in use are a great idea, and its not only the Yanks that have this sort of thing (ref.
PhilD's note re- LAX SFRA above...
Take for example Sydney's Victor-1 VFR route (ref.
Sydney Basin Pilot Guide and
photos). You have to to follow the coastal cliffs and remain not above 500' in order to stay under Sydney's Kingsford-Smith international airport approach and departure routes, and must announce your positions using blind calls on V-1 frequency 120.8 (a separate frequency for Sydney Radar 125.8 is provided in case of emergency and you need to speak to a controller). Aircraft on the V-1 frequency talk to each other as an aid to regular "see and avoid" separation. Works great in my experience fo a few flights through V-1 while there on holidays in a rented Arrow at Christmas time.
I think the merits of this approach are many: safer, easier, no cost, and reduced ATC workload. I can't think of any negatives. In my view this would be an ideal solution for the Manchester LLR. Does anyone know why this approach is not favoured here?
Andy