Read: WATERLESS. I wish I were making this up. We're talking NON-FLUSHING URINALS.
If I had to guess, the shit-smelling goop which 'bubbles up' from the drain is some sort of sanitizing enzyme which in theory nullifies the requirement of a flush, but I'M NOT CONVINCED! Its odor, co-mingled with the strong scent of urine (and I'll be honest, even its disturbing presence and *ahem* manner of conveyance) GROSS ME OUT!!
How green is too green?