Everyone's milage varies. For some people, frequent flushes work. For me, I have to wait at least two weeks between flushes to get any stones out. Even then sometimes a flush results in no stones.
I flush every two weeks and get stones out usually on every other flush. The more sluggish your liver and gallbladder, the longer it will take for stones to move forward enough toward the main ducts to be expelled. Experiment and see what works best for you.
Just keep flushing on a regular schedule until your liver is clean.