Urea is bad for your plants, it is the substance that carries excess nitrogen out of our bodies and fresh piss is WAY too hot for plants. This is why you must compost chicken manure because they piss and shit together, so you must compost it for the urea to break down into useable nitrogen, also the reason horse manure from stables must be composted, but horse manure from the field is good to go.
As far as human shit, DO NOT DO THIS, untreated human shit is full of all kinds of nasty stuff, as far as that goes do not use manure from any meat eating animal. Ever heard of e colli and salmonella, we catch these things because we eat food grown in 3rd world countries that fert with human shit, doesnt affect them because all the vulnerable ones have died off and the ones left have immunities.
Now with that being said treated human waste from your local sewage plant will not look like shit at all it is sort of sandy, and it will absolutley grow some good plants, but dont use much it, is strong stuff. I know a guy who works at a sewage treatment plant and he used it on some tomatoes that he had not intended to mess with. By the end of the season they were about 15 foot tall with trunks about 4-5 inches in diameter.