I’ve looked at webmd for info concerning external nose oil. I can’t understand the purpose of it. All the info they present evolves around acne which isn’t a problem for me. Are we the only species with this oily nose? Is it some kind of sexual arousal gland? I’m sure the T.M. are curious too.
Could be to protect from cold in an area where the skin won’t get much warmth from within (with a little blood circulating behind it, and bone and air also behind it). I only say this because I remember along time ago watching some show where they said that if you were skiing, one way to protect from chapped lips (assuming you have no balm on hand) is to take some of the grease from your nose and wipe it on your lips to help.
I sniffed out this information 