I participated in a recent chicken process day at a neighbors farm and learned something interesting as well as useful. The butcher was associated with a feed store, and sold the expensive stainless cones to hold the birds for killing- but for his own processing operation, he nailed several road hazard cones to a horizontal plank folding the flap that the cone sits on up 90 degrees and nailing to the board. He trimmed a couple of inches off of the rubber road cone to allow for more room for the chickens heads- they hang down lower with less constriction. He told me in earnest, partly in jest, not to share his personal cone setup, as he makes a living selling the expensive cones. I would not suggest stealing roadside cones, but have seen some damaged cones discarded, (run over, bases torn) and these did the job at a fraction of the cost.