At most companies, thousands of employees coming to work in dirty clothes probably wouldn’t be considered a good thing.

But last spring, the Levi’s community engagement team decided to get attention by getting dirty. They launched the #gowaterless challenge and asked employees to wear the same pair of jeans every day for a week without washing them to raise awareness about the company’s water conservation initiatives. Employees competed on their … er, endurance, as well as their fashion sense—they uploaded and shared photos of themselves in their dirty jeans via Instagram, and liked and commented on their co-workers’ photos. The company then opened the campaign up to the public, and by day five of the challenge, more than 5,000 images had been shared on social media. Better still, more than 11,000 accompanying Water<Less challenges—small water-saving actions individuals could take on their own—were completed. Each action triggered a donation to from Levi’s, providing clean drinking water for life for some 4,100 people.

I’m not at all surprised the Levi’s effort was so effective. Having created our own Impact at Work program, which helps employees launch initiatives that make social or environmental change in the workplace and the world, we’ve identified certain patterns that tend to hold true among the most successful initiatives. So what can we learn from the Levi’s campaign?

1. Align the effort with the culture.
Levi’s culture is all about authenticity, and what’s more authentic than airing your dirty laundry for all the world to see? Allowing employees to express their personalities through fashion speaks directly to the company’s brand culture.

2. Align the effort with the business strategy.
Levi’s had a great new product—the Water<Less Jean—and used the #gowaterless challenge to focus attention on how that product makes a larger impact on the environment. When it’s easy for employees to see how their own personal interaction with their company’s product makes a larger impact, enthusiasm and engagement follow naturally.

3. Dangle a carrot.
Admit it—who doesn’t perk up when there’s a tangible reward? Levi’s gave the nine most stylish #gowaterless employees $1,000 each to donate to the water-related nonprofit of their choice, giving them an incentive to make a direct contribution.

4. Make it personal.
What do employees care about? What can they see, touch, wear? Engagement initiatives that speak to employees’ personal values, and allow for hands-on interaction, have a better chance of taking off. We can see this with the Levi’s campaign, and we see it over and over among our own members. That’s why our Impact at Work Toolkit specifically walks users through a stakeholder mapping process to ensure that impact initiatives resonate with both leadership and support staff.

5. Make it easy.
Asking employees to not wash their jeans was about as easy as it gets. And since many employees are already using social media tools such as Instagram in their personal life, using it in their work life is a natural extension. The #gowaterless campaign is a perfect example of how employers can capitalize on existing habits and interests to increase engagement.

One last thing Levi’s did right: It turned to its employees to drive the campaign. “We encouraged our brand’s biggest champions—our employees—to personalize our water initiatives in a very fun, grassroots way,” says Becca Prowda, Levi’s senior manager of Corporate Affairs. “That buzz translates authentically into the marketplace where our messages continue to resonate with our fans.”

An organization’s employees are one of its greatest assets. This is what drives Net Impact’s Impact at Work programming, and it’s what made the Levi’s #gowaterless campaign so successful. Employers who give employees the opportunity to do good will see a real return on investment—for their brand and for the world.