re: Hog Trapping advice - figure "C" trap?

We caught 9 of them at 1 timein atrap similar to that in Texas last year. Only difference is that ours had a swinging door with a spring attached. The door was propped open with a 2' piece of wood tied to a cable about 30' or so. The cable was then run through a couple pulleys to the opposite side of the pen. We spread corn throughout the pen and when the hogs made their way to the other side, they tripped the trigger cable and the spring pulls the door shut.

I was told you don't want to shoot the hogs in the trap after you catch them because it will take a very long time for more pigs to go in the trap with the blood and stuff in there.