Well, I haven't read a lot about liver flushes. My sister highly recommends them so when my husband started experiencing pain in his liver, we tried a flush. He got out some small stuff and a lot of flaky stuff and the pain disappeared.
What I had heard---and remember, I haven't read a lot about this---is that when the gallbladder becomes too full of stones, you start getting them in the liver. So yes, they ARE gallstones---but it's only because the gallbladder and liver are connected.