I've heard that leaving a t-shirt works very well because it's been against your skin and has the most scent. I've left clothing before and never had a problem but I don't know if any wolves or bears were around to take it anyway. I don't know any way to prove that it works without a live predator to test it.
I'm not sure that peeing around it works. I've heard of guys peeing out their tree stands and still having deer come in. A deer isn't a wolf, of course, so I don't know if it works or not. However, if you have to pee before you leave the deer, you might as well do it.
