Is the tail skin important for BTO? Or is it the fat? If you skin the tail, is it worth while to put the rest of the tail into the BTO bucket?

I've always done it skin on, but I've seen pictures and video of guys doing it skinned. The fat is where most of the oil is going to come from, how much of a different odor the skin is going to add I'm unsure.

Rendering the tail material with the skin on will produce a dark colored oil. If you skin the tail out with only fat and bone the oil will be more golden and clearer. The same effect with any other fat rendering process. The pure fat only with no tissue will produce the clearer oil and suet colored fat as it chills. The odors are slightly different. I can smell the difference and prefer the odor of the unskinned tail oil.

Yeah mine looks like used motor oil. I really like the smell of it myself, but I've never smelled it made out of skinned tails.