It's in the books by Aajonus Vonderplanitz titled "We Want to Live" and "The Recipe for living without Disease".
"The Recipe..." has a recipe for veggie juice that is made for detoxification of mercury that includes cilantro of course, but he mentions that you should eat a raw fat (like raw butter or raw eggs) right before injesting the veggie juice or the mercury gets mobilized without being removed from the body.
He's been 100% correct on everything so far, so I have no reason to doubt his findings from 45 years of practice.