After reading the article, I would admit it is a very novel way of caring for your denim from the director of brand concepts and special projects at Levis Strauss co., the founder of the denim culture.
Here is a small extract from the article :
After six months of wearing a pair of jeans, Mr. Chiara does a comprehensive cleaning; his method could also be used by those who like to wash their jeans more often. Usually, he fills a bathtub to about six inches with room-temperature water and adds two tablespoons of Dr. Bronner's Magic Liquid Soap, which he likes because it is mild. Then, he immerses the jeans in the tub, laying them flat.
Sometimes, with dark jeans, he'll add 1/8 cup of white vinegar to the water. "The vinegar sets the indigo and keeps it from fading," he says.