".......most scent comes from your neck and head."
Really? I would have thought, your anal cavity, (respectfully), your breath, and your arm pits, frankly!
Dirt on your face, ..........we used to do that for camouflage in the military, and I suppose it could suffice for killing scent too,
I remember in my youth, growing up above Caribou, Maine, we used to have to try and kill our scent so that we were not attractive to the "no see ums" (bugs) up there.
I'm assuming 100 yards max, downwind, with a potential for being typically 40 - 70 yards away. Not sure how typical that would be, (and I don't "bow" hunt), but .....
"If the river sounds; somethings coming"