RE: training a coondog not to tree "trash"
For deer, a good bet isa shock collar, but you can only shock the dog when you know good and well that they are chasing a deer. Otherwise, you could do more harm than good.
As far as treeing trash, you should probably be happy with all game it trees at first, and back off the trash. They say to simply walk away when they tree "trash." I don't know because I let my dogs tree whatever they want to tree. I'd rather hear my dogs treeing on a possum than to have to go home having heard nothing all night if there weren't "on game" critters moving about.