Flushing does work. My wife did it though not this particular one.. Essentially it uses oil to lubricate the duct and by orienting the body in a particular series of directions the stones come out. Lots of them, some quite large.
However it doesn't fix the problem. My wife did it three times but continued to have the debilitating gall attacks because the body just keeps making more stones.
Stop the agony and have the operation to remove the gall bladder. It is done by keyhole surgery. My wife said she which she had done it right away and hasn't had any trouble since.