If you are going to do it, use a recipe that calls for a lot of apples, apple juice or apple cider vinegar in the week, or weeks leading up to the flush http://wellnessmama.com/38/liver-cleansing/. The malic acid in apples is supposed to have a softening effect on gallstones/liver stones http://www.liverdouche.com/apple-cider-vinegar-shots--orthophosphoric-acid-drops.html. Orthophosphoric acid supposedly has the same effect.
Kris, If you've never done a flush before, I have to let you know that you will produce a lot of "stones" during the flush. These are either clumps of thickened bile in the biliary ducts in the liver, or are a result of the action of bile on the olive oil. I put the word stones in quotation marks because these "stones" are very soft. It sounds kind of disgusting but, If you want to know whether or not you got the actual stone of concern to move out, you'll have to collect all of these somehow, maybe in a strainer. Then, wearing gloves, of course, you'll have to squish each one until you find the actual gallstone. The way this flush works, is that it causes a lot of bile to move through the bile ducts and gallbladder in a short period of time. The hope is that the force of this rapid movement of bile will sweep up any hard stones and move them through the bile ducts.