Elderly people in particular should take winter/kidney tonics which can greatly improve their body constitution and promote better resistance to illness. So when they find that a toxic substance has a positive effect, hormesis is assumed almost by default. Adapting a primarily paleo diet (minus exceptions above) has changed my palate. Coming from the thistle family, burdock has been in used for two centuries in treating a wide range of health conditions.
I recommend Paleohacks Cookbook as a great starting place for Paleo beginners and as a great supplemental cookbook for Paleo experts looking for new recipes and creative takes on the Paleo diet. I have done "pulled" pork in the oven for 8 to 10 hours with out a problem. I.