Blood purifiers have been traditionally recommended to clear up morbid conditions such as cysts, abscesses, acne and skin eruptive diseases like chicken pox and measles. They are also traditionally viewed as anti "major issues" remedies.
How these herbs work is not fully understood, but it appears that many of them stimulate liver detoxification systems which help the body process toxic substances for elimination. They may also improve lymphatic flow, which drains the fluid from the tissues and clears up infection and cellular debris.
