NAC is good for protecting/rejuvenating the liver. A doctor told me they keep it on hand in emergency rooms for that purpose. Hulda Clark explains the mop up procedure pretty good in her books, but I don't have one handy to look it up and read about it. Seems like she said that when worms die off, toxins are liberated, and you need to clean them out, or assist the body in getting rid of them.