Reviving this old thread, because it was the closest I found.
I'm looking for details, maybe I'm over thinking it, but here goes.
I'll use my KLVUK a lot around the yard. Everything leaves sap. Trees, blackberries, ivy, everything. When I'm done I'll wipe it dry, then wipe it with a mineral oil rag. (Oh, I did a vinegar patina back when.) It's looking good. But, some of the sap doesn't come off. I can rub it with the oil cloth, but it stays. Whatever, it seems fine.
Well, my AK I'm not using as much, it still looks so pretty, mirror finish and all. But it still has some sap marks from what little I have used it. I've wiped it, soaped it, oiled it, rubbed it some more. The marks are still there. Are they a well earned beginning of a nice patina? Or, are they rust spots waiting to happen if I don't put in a little more elbow grease and get rid of them? I'm hoping for the patina one. I'd just hate to find out in a few years that it was the beginnings of rust.
And now, I just got a 21" Chitlangi, she's a beast. I don't want to keep these knives in the closet, but I want to feel more comfortable using them.
So, tree sap and plant oils/resins. How hard are you trying to get it off? Quick wipe and then oil it up? Weekly hard wash, and scrub it off? Don't even worry about it, because it makes the patina?