I suggest those interested visit the MEDX Y! board for a discussion of the various issues by persons far more tuned in than I am. Note the narrow potentially commercial application envisioned---treatment of liver transplant patients to clear virion from serum before new liver is planted.
I am thinking prophylactic therapy, like a vaccination---treat healthy, uninfected individuals to prevent HCV infection. Practical? I do not know. Half-life of the antibody? Again I do not know.