I am sorry to say to you that the only thing that can save your brother is likely a liver transplant. His liver is in failure and no treatment can return his liver to normal function.
He needs to be under the care of a hepatologist associated with a liver transplant center.
Black salve, also known by the brand name Cansema, is a dangerous and controversial alternative cancer treatment. The product is commonly classified as an escharotic—that is, a topical paste which burns and destroys skin tissue and leaves behind a thick, black scar called an eschar.