Boil a small onion, 2 cloves of garlic, 1/4 teaspoon of EACH - sage, thyme, ginger, cinnammon and cloves (and a pinch of senna - or some Childrens Castoria) in about a quart of water. Boil it hard for about 10-20 minutes. Cool and strain. Put in the fridge - put about 1 teaspoon of this into 4 ounces juice or water and sweeten it with sugar, honey or molasses so he will drink it. Taste it yourself first - if you can tolerate it - he will too.

Feed as much as he will take 2 times per day until he begins to expel his parasites. Do whatever you are currently doing to make sure his bowels move until the mass is dead and expelled.

Continue feeding this until all visible parasites are gone. Usually a day or two is enough.