Matt Damon takes charity seriously. The star of "The Monuments Men" recently accepted Ben Affleck and Jimmy Kimmel's ALS Ice Bucket Challenge but, in an effort to raise awareness about global water conditions, the Water.org co-founder decided to pour something a little different over his head: toilet water.

The actor then proceeded to nominate three notably charitable celebrity pals.

"It posed kind of a problem for me," explained Damon as he geared up to take his ALS Ice Bucket Challenge. "Not only because there's a draught here in California," he continued, "but because I co-founded Water.org and we envision a day when everyone has access to clean drinking water. There are about 800 million people in the world who don't. So, dumping a bucket of clean water on my head seemed a little crazy."

Damon went on to detail the fact that Water.org also promotes bringing clean sanitation to people who don't have it, which is why he filled his challenge bucket with the unsavory water, and ice.

"This is truly toilet water," Damon insisted. "I've been collecting it from various toilets around the house."

The "Ocean's Eleven" actor elaborated on his reasoning behind using the questionable liquid, saying, "For those of you like my wife who think this is really disgusting, keep in mind that the water in our toilets in the West is actually cleaner than the water that most people in the developing world have access to."

After ladling a little extra toilet water into his container, Damon ventured outside, held the bucket over his head, and doused himself.

The actor/philanthropist then continued, nominating three A-list stars known for their work with various charitable organizations.

"George Clooney, my favorite actor; Bono, my favorite musician; and Tom Brady, the greatest quarterback of all time," challenged Damon.

No word on whether the actor showered after the camera stopped recording.