Yeah but hey like spanishfly says flatus stinks but hey you already knew that, then again so does urine if is too concentrated, hence the dilution. I can't see people using fart gas to feed their plants though, that sounds all kinds of wrong. Have you tried using urine DMZ? Great avatar by the way, got to love breaking bad.
I was on the main forum page, and I seen the title of the thread and just had to check it out haha. When I clicked on it, it brought me to this last page which I assumed was the first. It was only after I posted that I realized it was such a long thread.
The urine composition stats are quotes from Wikipedia which is quoting extensive NASA research. I brought it up because N isn't isn't listed as one of the top ingredients of urine. I just couldn't see how urine would provide significant N if it's not present in any great concentration, but then I read the first post.
I brought up farts because I remember that most of it is N. Which led me to believe that the body gets rid of extra N through gas rather than liquid. When it says odorless, it's refering to the specific gases listed. Not the fart in it's entirety.
Anyways, no I haven't tried it personally. It would be cool if someone set up an actual experiment with their plants to see how it effects growth. I'm gonna be on the fence until I see documented results from a reliable experiment.