in my opinion Liver Flushing is healing the root of the problem: missing bile. The stones trapped in your liver were impairing the bile flow. Flush after flush bile flow is slowly increasing, resulting in improved digestions and less toxins around. As a result your kidneys are getting less stressed and your bags tend to disappear.
This does not mean that some days after a LF, when some toxins are inevitably recirculated (in special in absence of a colonic), the bags under the eyes may reappear for a while..