not only do i use the meat for bait, many times i stuff a front leg cut off from skinning down the hole after putting a dash of fox gland lure on it. anything i snap and skin, i trim for bait, but no, i dont bother tracking what i've caught off of what, but i DO know i snap new fur off of snapped fur meat. pretty sure the last was coon bait on a gray, but who knows. meat taints and smells, and hungry bellies like things that smell.
I guess you could use a fox paw off a catch in the hole, in a new set, perhaps at a new location you are just setting up. The paw will have all the stink from the catch circle. Could try a grey fox paw if setting an area with almost all reds, or try either fox paw when doing a fresh coyote set.