There are natural alternatives. I'm not so sure I have a problem with the way mink oil is derived, if in fact it is a similar process to any other farmed animal use.
See this short Wikipedia article: http://en.wikipedia.org/wiki/Mink_oil
I don't get up in arms over cows and chickens being raised for consumption, so I don't see why I should feel differently about the mink. It sounds like they are using the entire animal, which I think is appropriate.
I am all about humane treatment of animals, and my food practices reflect that with the types of meat I buy, as far as I can reasonably control that.