There are anecdotal evidence that melanoma sufferers following the juicing
diet by Dr Max Gerson responded well. Dr Gerson included a potassium Iodide
solution in his diet.
Meanwhile, Dr Tullio Simoncini also uses topical Iodine
to treat skin cancers. He seems to use a common Iodine
tincture. In my experience alcohol containing Iodine
tincture dries up quickly and "burn away" the skin under the area of application when enough is applied.