Birds are left in the cone to drain out (into a bucket placed below said cone). Then the neck is held with one hand, while the vein is slit, then walk away for 2 mins while it drips (we do 2 at a time, so while bird 1 drains, bird 2 is being put in the cone. Once it's on the cutting board in front of me, it's a dissection. Same passionless detachment that got me thru years of science classes, get me thru butchering. Also if there's no need to store then whole, part them out as you go, split the breasts, leg quarters and wings now, rather than having to go back and rework it. take less fridge space and less fuss (i've been known to rig up marinades ahead, and put the meat straight into the marinades instead of brining them, use a sharpie to write on the sealed bag).