And to follow this up: someone read this law, and so decided to try it out. He was caught short in public, so stopped the taxi he was in, got out, put his right hand on it, and did what he had to, into a drain cover on the side of the road.
Only to get arrested.
The flaw to his plan was the fact he didn't understand the difference between urination and defecation. Whilst urinating seems to be fairly valid, defecating into a drain is far from it.