I've used bear grease, marmot oil, Neetsfoot oil and track's mink oil(grease). The very best was the slowly tried-out marmot oil (Hoary Marmot) and I'd have to say the second best for accuracy and clean shooting, was Track's mink oil. I didn't compare the two at the time, nor use them in the same gun,however that is my impression of those components.
I didn't find the bear grease particularly clean shooting, howeve the Marmot oil and Track's mink oil was. To only a slightly lesser extent, the Neetsfoot oil is also clean shooting in comparrison to my 'best'.
Those are my findings & extent of my testing with animal oils. It is possible some other renderings, like elk, deer, moose, caribou racoon or skink or ? might be better yet, I don't know.
I do know the best trail walk lube ie: most accurate/cleanest shooting, I've ever used was LehighValley Lube - both the Oxyoke and original formula stuff.