I just wanted to pass on a couple of pieces of information following on from your report back.
Liver spots can be genetic and are associated with ageing and exposure to the sun. Metabolism changes after a flush may cause the liver to become so overwhelmed with toxins that it cannot get rid of them. Oxidation within the body and the lack of antioxidants may also plays an important role and liver spots may be one of the results. Liver Flushing will be the most powerful therapy but the liver can take 6 month to detox so try and keep away from the sun for this period. There are some common recommendations for 'curing' liver spots on this link:
You also mention knee pain. I read in an old Chinese herbal book that a congested liver can cause rheumatic type pains; especially the right shoulder, right arm, right hip and right knee. These pains and skin conditions are also accompanied by itching, especially at night!