Is there a debate on whether stones in the liver exist? I really haven't looked much into this debate (as in what they are debating in particular), but if you simply type in "intrahepatic gallstones" there are a number of scientific articles on the subject. "Intrahepatic" simply means "within the liver," (i.e., not in the gallbladder).
Here is one example of a journal article:
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=8963394
There still might be a debate as to the frequency of it, or the health benefits from a flush. I don't know...