Gerry said:
"The second line is "Ja edu kuda sam tsar idet peshkom", which translates as "I am driving where the king himself goes on foot", which hints at the toilet, but actually means that someone is trying to outdo the king in a little unimportant matter, and is being rather foolish at that. "

I'd have to disagree. "Ya idu", however you which to transcribe the spelling, means "I am going on foot". It has nothing to do with "driving" in any sense, and thus the bathroom reference is correct.