If you're interested in learning to swear in Cantonese Chinese, the "Bus Uncle" has your back. This is a legendary video of an older Hong Kong man tearing a younger man a new asshole for knocking on his shoulder while he was talking on the phone.
Although this isn't dirty Mandarin Chinese, the Bus Uncle video still provides a great example of how Chinese swear words are commonly used. With over 8 million views on Youtube, Bus Uncle is quite possibly the most famous Chinese swear user alive.