Rickod,
Having grown up on a farm I've had to 'put down' quit a few animals. Everything from shooting my own animals who have become injured. Or dogs who I adopted and couldn't overcome their behavior problems (chasing domestic animals, or unstable behavior making them dangerous), or killing diseased or nuisance animals that show up. I've also hunted most of my life (can't find the time anymore) & even ran traps in my teenage years.
But what you describe is the most disgusting death I could wish on anything. If you've ever actually done this you ought to be knocked on your ass.
If you need to kill an animal, kill it. Step up, be a man, do the job, and take responsibility for it. If you have to arrange the situation to avoid legal problems, so be it.
But feeding that crap to an animal so it's guts can dissolve from the inside out is probably one of the most horrible things I could think of.
Poison is the tool of a coward.