I know this message is very old, but a photo on pinterest led me here--I also passed a pearly white, round, cyst-like object after a liver flush. The photo linked to this thread. This is exactly what I passed!
Did you ever find out what this was? It looks like a hydatid cyst, but it is hard to believe they could be passed (they typically attach to and grow into the wall of the liver or gall bladder).