The success of Wieden + Kennedy’s “The man your man could smell like” campaign for Procter & Gamble’s Old Spice is well-documented: explosive brand sales growth and a slew of top industry awards that continued last week with a Cyber Grand Prix at Cannes for its “responses” effort.

Less known, however, are the un-Procter-like working conditions that gave rise to the groundbreaking work.

At the concept stage, the campaign wasn’t subject to the usual rigors of P&G testing. Also, the approval process was streamlined, with Wieden taking its cues from a single executive. Both conditions are atypical for the world’s biggest spending marketer, but not for Wieden, whose core client, Nike, prefers to think with its gut.

P&G’s decidedly different approach—in process and execution—reflects a company loosening its tie, embracing change and moving faster, eight years after first storming the beach at Cannes.

One byproduct of P&G’s annual trips to the global ad festival was its introduction to Dan Wieden. The marketer first hired the agency in the summer of 2005 to work on a relatively small pet food brand. Eight months later, in early 2006, P&G shifted the bigger Old Spice out of longtime global agency Saatchi & Saatchi.

At the time, Unilever had goosed the U.S. with the launch of Axe body spray, suggesting, in a series of cheeky ads from Bartle Bogle Hegarty, that the product will improve a guy’s sex life. Axe not only introduced a category but set the tone, with great success, both in terms of sales and creative awards. Its splash partly spurred P&G to seek a new agency for an old brand whose equity was a whistling jingle.

What Wieden came up with—after some fits and starts—was a character that appealed to both the men and women who buy such products. Played by former NFL player Isaiah Mustafa, the “Man your man could smell like” exudes male confidence and savoir faire. But in storyboard form, the half-man, half-horse with a towel around his waist would have garnered quizzical looks in focus groups.

Former Old Spice brand manager James Moorhead acknowledged as much last year. The campaign might have been killed or neutered beyond recognition. Instead, P&G just did it, with Wieden demonstrating that agencies—great ones, anyway—can still influence marketers, provided they can demonstrate success.

P&G, though, being P&G, downplayed any hint of process deviation last week. A company representative noted that Moorhead had to vet his ad decisions with his boss and even suggested that his admission of no testing was a bit of storytelling.

Other agencies, however, are aware of the leeway P&G affords Wieden, if only because it doesn’t apply to them. “Obviously, we would love to have the same hall pass,” says a top agency executive.

Don’t expect the whirlwind success of Old Spice to change the time-honored traditions of P&G, which, after all, is a global giant with billion dollar brands. It may, however, make it easier to sell innovative—and award-winning—work.