The product description provided above (and from the jacket copy of the book) emphasizes what might be considered the "cute" aspects of vulgar speech. But the language of the vulgar/common/mean/low (and yes, I just equated the common with the low, because they share more with each other than either did/does with the elite) offers more than chuckles. It provides clues about the everyday lives of those who spoke it. By studying how quartermasters and criminals spoke, we learn about the ways low-life characters contributed to society, like a microbiologist studying the interpersonal relationships among the flora of the stomach. Most telling, we learn that the language of the low-life shares very much in common with that of the soldier/sailor. This Navy vet can't help but wonder why.
Anyone wanting to write about 18th-century British culture must read Grose's guide to the language of the time--not *refer to*, but *read*. It is not enough to spice up a manuscript with random terms from that milieu; reading The Vulgar Tongue: Buckish Slang and Pickpocket Eloquence cover to cover will contribute substantially to your being able to write with authority and authenticity about that milieu, as much as one reference book can.
This is a valuable guide to 18th-century Britain's underbelly. Though it is not a narrative, reading it as if it were provides the reader with as rich a story as any novel. I highly recommend this to writers, especially, who may find inspiration from reading it.