When using footholds at castor or similar sets, I always do 2 things- 1, if possible make a small cutout 18 inches or so wide, and the same deep. this squares him up coming in. Inside the cutout, I take the spade and make a ridge 2-3 inches high, and set the trap behind that. much easier and far better than any poke of guide sticks- he will hit the ridge with his chest coming in if swimming, and he will step over the ridge and give you a front foot catch like clockwork. If I can't make cutouts, such as rip rap, I'll use rocks, logs, etc to get him coming in square.....trappnman