There are a few damns, hells and asses here and there but they're infrequent and are only used a few times throughout each episode.
One episode contains a misspelled F-word (but it's only seen on screen and is never said), and in one episode, a string of f-words are heard in a video game, but never from Joe and Dave themselves.
Another episode shows the game House Of The Dead Overkill where the characters are heard spouting plenty of f-words. Again, never from Joe and Dave themselves.
The word sh*t is about as harsh as it gets otherwise.