Matt Damon will not poo til you can, too

Matt Damon gazes at a press conference of unusually well-groomed journalists. He has an announcement to make. "I'm going on strike," he says, to protest lack of sanitation in developing countries. "Not from acting, that would be too easy."

There is silence, then consternation. "What?" asks a bewildered reporter. Questions erupt. For how long will he strike? Will he refrain just from actual bathrooms, and do his business elsewhere? Will he forswear, asks a flustered TV anchor, groping for network-acceptable vocabulary, from "pee-pee and caca, or just pee-pee?"

Damon shoots back, quickly if not very helpfully: "You do the math." The press conference ends in tumult.

The surreal exchanges are scripted and the journalists are actors, but the scene is not part of a movie. It is the first in a series of YouTube videos put together by an unusual alliance of Google, Hollywood, social-media creators and a non-profit advocacy group, The campaign, which was launched on Tuesday and will build up to World Water Day on 22 March, hopes its combination of celebrity, social media and humour will appeal to young people and go viral on the internet.

"It was Matt Damon's idea two years ago: how do we persuade people to give a shit about toilets?" said Chevenee Reavis,'s director of strategic initiatives, during filming of the sketch at Google's YouTube complex in Los Angeles.

Shocking statistics – such as a child dying from a water-related illness every 20 seconds – did not on their own command attention, said Reavis, and had just a five-figure budget for its campaign. That would be enough, perhaps, for half a second of advertising during the Super Bowl, where a 30-second spot costs $4m.

The star is most popular with women aged 34-45 [ed: whaaaaa?], not a group which drives YouTube hits [ed: whaaaaaaaaaaaaaaaaaaa?]. So the campaign decided to use comedy and hip YouTube creators in an attempt to attract younger viewers. Damon's Hollywood colleagues, working "pro bono or low bono", helped write, produce and direct the press conference sketch which will launch the campaign. It was shot in January at Google's digital production hub for YouTube creators, a converted hangar once owned by Howard Hughes.

Producers appealed to extras, who played journalists, to keep the job secret, in order to maximise publicity later. "We need to launch with a bang. If you tweet this children will die," said one, only half-jokingly.

The campaign has trailed Damon's threatened strike, without revealing what it would entail, for months, via the website STRIKEWITHME.