A South Korea cosmetics company developed a line of beauty products which featured mud from the Boryeong mud flats as a main ingredient. Since the company couldn’t be bothered to spend money on commercials, the Boryeong Mud Festival was born so potential customers could feel the benefits of the special mud firsthand.
n 1996 a range of cosmetics was produced using mud from the Boryeong mud flats. The cosmetics were said to be full of minerals, bentonites, and germaniums, all of which occur naturally in the mud from the area. In order to promote these cosmetics, the Boryeong Mud Festival was conceived. Through this festival, it was hoped people would learn more about the mud and the cosmetics.
Source: https://en.wikipedia.org/wiki/Boryeong_Mud_Festival, http://www.emlii.com/78e50642/22-Breathtaking-Festivals-Around-The-World-That-You-Must-See-Before-You-Die