From what I've read Black Salve seems to be very effective for removing skin based tumours and lesions - such as cancerous moles and what not. Everything I've read says it needs to be in contact with the cancer it is removing but you don't say whether your DP's cancer is a lesion or actually inside the ear. I am guessing it must be deeper in the ear/head if it requires a big operation like you metioned to remove it. Is this a life threatening cancer we are talking about?
I hate to be skeptical, but I don't know that black salve will help...