Burdock root tea is the best blood purifier. For blood carried disorders such as allergies, rashes, hives and acne, burdock root tea could be the answer. Bring to boil and sit for 5-10 minutes and take every night for the best effects.. You can try saffron, sandalwood powder, turmeric and calamus root powder. I like the idea of using a tea for a few weeks and stopping. Then restart again a few weeks later. The therapy is more effective that way.