You are very right that Liver Flushes must be done more than once to fully decongest the liver. When a person strives to correct the causative factors for Gallstones while flushing, there is less chance of the stones recurring. Some causative factors are poor diet with too many refined foods, not enough healthy fat in the diet, parasites, use of drugs including over the counter, prescription and street, and stress. A diet of whole foods suited to one's unique body type and needs, healthy oils, lecithin, leafy greens, and apples will probably reduce and perhaps stop stone formation for most people.
My primary health care practitioner is a Chiropractor/Naturopath (he has two doctorates), he is the one who got me started with liver flushing.