But it can be fun and educational to share old phrases with the younger crowd. A group was asking me how my new car ran and I told them “It runs like a raped ape up a tree!”. Two people got it and the other two were most interested in where that came from. My young boss even wrote it down on his whiteboard.
So tequila and soda with a twist of lime is a ‘frou-frou drink’?
Of course.
You can’t spell “fruit” without “frou”.
There are some Texans who would disagree with you. 
They’re Texans. They’re wrong by definition.
Yeah, but… Never mind.
Non-native Californian and I use it very occasionally. Have no idea where I first heard it or picked it up, but it was certainly a long time ago. Never occurred to me it might be obscure - whenever I have used it people seem to know what I mean, but I suppose it could just be context.
Like gnoitall I also use the phrase “frou-frou drink” but usually only to describe a beverage with a lot of fruit garnishes and maybe a little umbrella, or one with mulitiple liqueurs or juices added to a basic booze and given a fancy name like “Corpse Reviver” or “Blackberry Bramble” (both of those on the menu of a restaurant here in St. Louis Missouri). Even a Margarita I would not call a frou-frou drink: but a Chocolate Martini or a Brandy Alexander I would classify as such.
This is reasonable. Everyone who works with the concept of the “froufrou drink” has a different threshold for “frou-frou”.
Mine is very low, others’ are welcome to be higher, and yet others may not even consider the concept valid because exotic, complex, fruity or highly decorated drinks may be what they consider to be normal drinks.
I know that this is a controversial position to espouse in IMHO, but as in all things subjective, YMMV.
From the philological/linguistic perspective, however, it would appear that the setphrase “froufrou drink” may be independent of “froufrou” as a general adjective. I certainly never use that word outside of its phrase, and if I hear that word in a different context I’m still going to decode it as “froufrou like a froufrou drink”.
I was a bit taken aback to see a thread about the rustling sound petticoats make (surely petticoats are not a thing in the 21th century?). Does the term have another meaning in US English?
I’m from the East coast, I know the word and I’m sure I’ve used it, I wouldn’t be surprised by anyone else using it.
Ohio. I use it. I tend to say fancy more these days.
I know I’d heard of this drink. It was invented in 1863 in Paris.
West coast here, I use it. Mostly when talking about drinks, but also when discussing special cleaning “The big boss from up-state will be here on Friday, we need to frou-frou this place up.” Nobody has ever indicated lack of understand but that could just be because they got it from content.
“bougies” are candles 
Personally, I pronounce it “bourgeois”.
What is the boundary between figurative or tropical usage and slang? “Frou-frou” meaning “showy” is hardly a literal use of the word, but does it rise to the level of slang? Also it may not be a common word, though I too have heard it spoken.
I guess elaborate petticoats are more likely to make frou-frou sounds than other kinds of dresses? Though if people in the 21st century are imagining ostentatious petticoats, or especially if they are not, and talking about frou-frou (a frou-frou drink???) then we are moving firmly in the direction of slang.
ETA there is a different French adjective farfelu people may have heard, however that means “bizarre” rather than showy.
This is how I generally use it - from wikitionary:
2. Highly ornamented, overly elaborate; excessively girly.
They ate in a frou-frou restaurant at the top of a skyscraper.
I don’t use it because I find it as hard to pronounce as “rural”.
As, The Rural Juror.
Yes. Sucking a lemon, licking salt, and downing a shot of tequila is not frou-frou. Tequila and soda with a twist is.
Just kidding. A drink with a paper umbrella is frou-frou.
I use it all the time. I’ve lived in Illinois, Indiana, Baltimore, Ann Arbor, and D.C.