I agree with huntman to a point. But i also think that human piss will not alarm deer unless you are kicking another type of un natural scent on your boots, like gasoline, or other smells related to humans. Basiclly, if you are scentloked or clean with clean rubber boots and piss in a scrape, i don't think it would be a problem. The deer will just think it was another animal.
Deer are very curious animals don't forget!
This is a very interesting topic, i like reading the responses.

Brian