Narcosis bar

Nitrogen narcosis is a condition similar to drunkeness which affects people exposed to nitrogen at high pressure. It can be fun, and is reversible once the partial pressure of nitrogen drops below a certain threshold. So the bar would have to be pressurised to, say, 4atm. No booze necessary. The doors could shut at 9pm (say), and the bar would be rapidly pressurised until the punters were narked off their faces. It could then adopt club-like features such as amusing visuals, loud music, chill-out rooms etc. Anyone having a bad one could be dragged into one of the many decompression booths and taken outside. At the end of the night, with everyone thoroughly knackered, the pressure could s-l-o-w-l-y be lowered, extra oxygen pumped in to combat the bends, and the revellers turned stone cold sober onto the street after a safe period of time. Maybe it would be best to build it beneath the surface to prevent children chucking stones at the windows.