In case anyone thinks Tom Emery is just being annoyingly misleading, no. He's absolutely correct: "drop the kids off at the pool" means "go poo". Obviously, this isn't something to say in polite company, if you need to go to the bathroom you can just say "excuse me", or better yet say nothing and leave the table.
It's a very common expression in the US and just means taking someone and leaving them like: I will drop you off at school. Never realized how funny it actually sounds.
@Dan: It's pretty common in Australasian English. Obviously, it's intended for humour, though it's a bit cliche now. I still prefer it to "I need to go to the little boys' room"...that one annoys me to no end!
@Mahmoud: you can find many slang expressions like these at www.urbandictionary.com. Just remember that Urban Dictionary is a wiki...that means a lot of the entries are of low quality, probably written by naughty 13-year-olds with too much time on their hands (when I scroll through the archives, I only recognise about 20% of the expressions in there).
And, of course, the usual word of caution: be very careful when using rude words and expression in another language! The difference between "funny" and "offensive" can be much harder to tell than you think.
If you aim to understand these expressions, however, Urban Dictionary's a useful tool for looking up slang that "respectable" dictionaries won't tell you :-P