After using only one dose of Julia Chang's Chinese Bitters I had the best flush results ever. Got 4-5 times more stones than the previous 8 flushes. I have also started using Gold Coin Grass.
As per a discussion with Julia, I am using GCG in the morning before breakfast with the Bitters before lunch. According to Julia, GCG should be used in the short term preceeding flushes. The Chinese Bitters can be used indefinitely, provided that you take a periodic break from them. She uses them everyday during the week and takes a break during the weekend.
By the way, Julia is a very friendly and knowledgable woman. Her herbals are also very affordable given how much she gives you and they are very strong!