Centaury is a bitter herb that hasn't been discussed here really. I found it because it was the main ingredient in Ann Louise Gittleman 's forumula. I had really great results with it, but then it caused my appetite to increase, so I had to stop. I think I had a non- parasite issue going on with hormones. For me, it worked great, but it was a pain, I had to buy the dried herb, grind it and capulate it myself.
When I felt I had something in my throat, I took tumeric, clove, ginger, and fennel for a week. Whatever it was went away.
Then there is always raw garlic, that would work too :)