I am a trained, experienced and very adept negotiator. I do a lot of contract negoatiation, coordination and execution for a living in the commercial construction, development and realestate world (internationally). So I will tell you, there actually IS a time, a place and a use for vulgarities (swear words) up to and including the "F" word in certain professional & hostile situations. It is reserved for a very specific situation and is a tool designed to affect a certain outcome. The frustration should be orchastrated and controlled when going this route, even if the emotion is faked (which it should be). I have only gotten the proffessional opportunity to use this twice in 18 years. It was fun.
That said, the use of the vulgarity here does not fall into the specific intentional use to which I refer. But it does certainly have the same affect. It draws attention and focus on what spurred the "emotional outburst". It has had the affect of forcing consideration. While it is not professional, her use of the word "$h*t" has been effective, ironically.
Judiciously used very effective my mom would use the Chit word from time to time it stopped all bad behavior in its tracks