A sauna or steam room might help if he can tolerate it. I am very sensitive to heat, and become extremely uncomfortable in the heat. I can't tolerate a suana or steam room. Some benefit greatly from them. If he does use one, then he needs to be sure to take in enough water, potassium(milk, vegetables or vegetable juice would be good sources) salt, calcium, magnesium, and zinc.

Perhaps he could try the detox teas and the licorice tea, and try eating the caveman diet for a few days(perhaps just salad,steamed vegetables, chicken breast or lean beef. Detoxifying herbs like dandelion, ginger and and alfalfa might help. Can he tolerate garlic? That is also good for detoxification. Have you thought about a parasite cleanse? Some parasite cleanses contain laxatives so they might be annoying to use. The Kroeger Wormwood Combination has no laxatives added(although the black walnut green hull extract and wormwood that it has have very mild laxative properties). Many here have had parasites, and improved quite a bit from a parasite cleanse.