"Breathe responsibly," visitors to Bompas and Parr’s walk-in gin and tonic cocktail cloud of breathable beverage are told.

It sounds like a spoof: A giant mist, full of gin, pumped into a room, which gets you drunk. It looks like a spoof: Bompas and Parr, two Old Etonians dressed in white coats and bow ties, are greeting the public and leading them down into the murky depths of their mad invention.

The quirky side-street shop, set up by the inventors, both 25, is simply labelled ‘GIN’. Bravely, we don the special suits designed to keep our clothes gin-free inside the UK's first walk-in cocktail. We look like oompa lumpas. Actually, we look like ghostbusters: it’s fantastic.

All the ghostbusters are led into an Eighties-themed bar and are left to wander down into the gin-mist room. It’s sparsely decorated (there is a giant lime and a big straw on the wall) and incredibly weird. You can’t see much, due to the mist, but you can make out the shapes of your boiler-suited friends against the lime-green light. Most people have gin and tonics in their hands to supplement the six litres of alcohol that is being pumped through the ‘mistifier’.

The mist tastes sweet and tangy – like an excellent gin and tonic – and is actually very satisfying to breathe in. None of us are quite sure if we feel drunk. Spending 40 minutes in the room is supposed to be the equivalent of a single cocktail but presumably heavy breathers (athletes and brass players?) will inhale the most.

Bompas and Parr have used a team of doctors to calculate the ‘mixology’. An ambulance is on standby and a chemical explosives expert has been consulted to ensure the heady fumes of booze don’t just explode. All this is a bit unnerving, but Bompas reassures me: “This is the most sexed-up cocktail you’ll ever have”.

As schoolboys, Bombas and Parr would skip lessons at Eton to go and sample exciting bars and restaurants. The drive behind their projects is to take a fun but far-fetched idea and make it happen in the real world with the aid of a team of experts.

As well as having created a fun and fresh experience, Bombas and Parr are responding consciously to the history of gin in London, having fronted their advertising campaign with a jazzed up version of Hogarth’s Gin Lane.

The walk-in cocktail is a genuinely exciting concept and if it kicks off, could help change the way we think about our relationship with alcohol.

Alcoholic architecture is at 2 Ganton Street, W1F 7QL, on April 17, 18, 23, 2 and 25 with timed entries at 7pm, 8pm and 9pm.

Tickets are available from www.jellymongers.co.uk

People must be 21 to enter.

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