True Gallstones are created in the liver and enter the gallbladder along with the liquid bile, gall=bile. The gallbladder is a storage sack where the bile is concentrated and then released as needed for digestion, usually after fatty foods are consumed. When the gallbladder becomes so full of stones that the bile cannot be easily released, the problems like pain and nausea occur. Common symptoms of gall stones are right quadrant pain especially after eating fat, passing quantities of undigested food in stools, and pale stools (from lack of bile).
The gallbladder/ Liver Flush is simply using the body's own natural actions to force the gallbladder to contract more forcibly than usual and release its store of stones and old bile. The sack is quickly refilled with more bile from the liver and the process of concentrating the bile and receiving even more liver stones is repeated. Flushing every two weeks is important because the bile is constantly moving down from the liver into the gallbladder. The use of acidic juices are said to be cleansing to the liver, but the clogged biliary ducts will continue to pass stones and old bile into the gallbladder. Symptoms of liver congestion may actually worsen for the first few flushes because so many toxins are being released. As flushing continues the stones will become fewer in number and will not have nearly as much of the distinctive oder of old bile and gallstones. True Gallstones will not have seeds in them, but may contain bits of liver parasites that can resemble seeds, grapefruit pulp, or flat white bits about the size of a grain of rice (but flat). A true gallstone cannot be mistaken for anything other than what it is, both by appearance and odor. Take a look at the Image Gallery and compare stones from removed gallbladders and those passed in flushing.
I know a lot of doubters report finding seeds and pulp in their "stones"; and describe their stones as soft and mushy. I somewhat doubt these are true stones from the liver, but perhaps newer bile that has been released from a normal gallbladder and has concentrated itself around seeds and such in the intestinal track. When the colon absorbs the moisture from its contents, the blobs of bile become thick enough to resemble stones, but are not the real thing. Anyone who has flushed hundreds or thousands of true Gallstones and has experienced the benefits of Liver Flushing can tell you that the Liver Flush is the real thing.
(I know this is a very simplified explanation, but hopefully will give a picture of how flushing works to cleanse the liver)