Don’t pee on it!

I have heard that applying urine to a jellyfish sting is the recommended treatment, but today at the discovery channel website, I read the following:

If you are ever unfortunate enough to get stung by a jellyfish, you’ll have some small consolation in knowing that there is no need to add insult to injury by asking someone to pee on you. Experts recommend carefully scraping off any tentacles that have adhered to the skin and treating the sting with vinegar, baking soda, ice packs, salt water, hot water or even meat tenderizer ? but definitely NOT urine.

Personally, I’ve always let the effects of the stings wear off with time. They can be pretty painful and itchy, but this usually passes pretty quickly. To be clear, though, I’ve never been stung by a Sea Wasp or Portugese Man-of-War, and I’d probably not be content to just tough it out in those situations.
If I remember correctly, the reason why urine is supposed to be an effective treatment is that it contains ammonia. In the list above, I don’t see amonia at all which makes me wonder if the whole urine treatment is the result of someone spewing out a whole lot of BS, or the result of a really twisted practical joke.
From what I can tell, the nematocysts (stinging cells) are proteins, and the best way to neutralize them is with something that would bind with or destroy them without further aggravating the wound. Perhaps that is why ammonia is not recommended- because applying ammonia would have an adverse effect, offsetting any of the benefits.