My experience has been "make it snappy" (i.e. "hurry up"), and the only time I encounter the word "swell" (not the sea type of swell), is when it's being used sarcastically. It used to be used sincerely, but because it's so old, the sarcastic use is the only one these days.
vulgar argot has changed by about 50% word use and term definition since 1920, english itself maybe around 15%.
there's a lot of terms that the contextual use is gone, or the rationale is gone, but the word has moved on to other uses. take chicken, for example, and the cuts to be had:
in the 1920s, it was considered the height of vulgarity to directly mention a term relating to a bodily part, so to avoid offending people, especially spouses eating out, the terms "white meat" and "dark meat" were used, to avoid having to say chicken BREAST, or chicken THIGH. sounds pretty ridiculous to us today, but back then it'd be like someone being asked to choose between a "chicken ass" or "chickie titties" - improper. the result is today, the terms have slightly seperated, into white and dark referring to loose meat, i.e. cut off the bird, and "thigh" has become "leg" while "breast" has stayed the same.
The word "gay" of course has been hijacked and become a euphemistic code word.
The term "honor" is now largely unknown to congress.
But not to worry, if one misuses a term there will almost certainly be a pc fussbudget in the area to wag its finger and instruct one as to propriety.
"fussbudget" archaic now, sadly.