My experience with flushing has been a positive. Coming home from the surgeon (2002 or 3) I jumped right in, since I wanted to avoid surgery.
CZ started off with Clark, Schultz etc., we have now many forums and different approaches so at that time it was the only option.
I had a 1" stone stuck in the gallbladder neck, the wall was 42mm instead of 3mm and there was inflammation. After 10 months I did another ultrasound and the stone was free floating and the gallbladder was back to normal.
The stone is still there and in the last year I have been using the bitters instead.
In an article from China, where they did liverflushing in the hospital but it took an average of 34 days, their conclusion was that only stones not bigger than 1 cm could be expelled. http://www.itmonline.org/arts/gallstones.htm