mink oil will not make them greasy it keeps the soft ,some of my skins are well over 12 months old with no problem ,they have not been over exposed to weather ,
any leather will need looking after , as long as you scrape well and stretch enough ,all I can say is try it see how you get on I will gladly send you one to see
what you get, test it, wet it, pull it ,I have a friend who trains his greyhound with my skins ,
its interesting I hope to tan a fox hide this year when I get the chance to skin one