Well I did 14 flushes so far.
I found out that a one hour hot bath between ED serving 1 and 2 helps expelling stones. According to my experiences the output is simply greater. Relaxtion and warmth are the two secrets.
Then I use only lemon juice which is more effective than grapefruit juice.
Plus:
Two hours following ES serving 4 the next morning I again drink about 100 ml olive oile mixed with same amount of lemon juice. In other words - sort of a "double flush".