I have seen them used and used the large game and smaller Bird versions myself stateside, most of the time I saw them used they either tore or split the rectal lining due to being used to quickly or not inserted deep enough, they do work if used correctly but they would not be my choice, a bit of careful knife work and you don't need one, plus as said in previous posts they are extra cost, more to carry, and look like something used by the Spanish Inquisition!