This book got swarmed over by my Chinese friends. I don't think they actually use A LOT of these words in real life, in regular conversation (so it wouldn't be as useful as one might think. what a shocker), but they found it hilarious that there was a book that had all these terms. The banana in our group (Americanized Chinese) found it especially interesting. The others kept laughing at his pronunciation, but he studiously kept at learning the words for "dildo" and "masturbation". Oh, you guys.

However, it is in Mandarin, which as far as I know, doesn't have enough roughness to it. (It's like an angry Ilonggo.) If you want expletives that hit the air like a whip crack, curses so graphic and dirty they make more delicate souls shudder and want to bathe and scrub themselves raw and clean, then learn Hokkien. (That's a compliment to the language. I think.) Some might argue for Cantonese, but I have my biases.

http://newnation.sg/2011/02/mandarin-is-not-my-mother-tongue-part-two/

Not exactly that useful but fun nonetheless.