Do you now, or have you ever, used any of the following words?
Catawampus
Dagnabit
Skullduggery
Rapscallion
Tarnation
Flibbertigibbet
Hugger-mugger
Absquatulate
Blotto
Hoosegow
Rumpus
Skinflint
Higgledy-piggledy
Piffle
Flapdoodle
Lepidopterist
Chalk this up to idle curiosity, and criminal proximity to a keyboard.
Catawampus - Yes
Dagnabit - Yes
Skullduggery - No, but I’ve come close
Rapscallion - No, but I like it
Tarnation - Yes
Flibbertigibbet - No
Hugger-mugger - No
Absquatulate - No
Blotto - Yes
Hoosegow - Yes
Rumpus - Yes
Skinflint - Yes
Higgledy-piggledy - no
Piffle - Yes
Flapdoodle - no
Lepidopterist - no
No:
Catawampus
Flibbertigibbet
Hugger-mugger
Absquatulate
Blotto
Higgledy-piggledy
Flapdoodle
Yes:
Dagnabit
Skullduggery
Rapscallion
Tarnation
Hoosegow
Rumpus
Skinflint
Piffle
Lepidopterist
I have only used the following:
Skullduggery
Blotto
And I have used the word lepidoptera whicj is related to Lepidopterist
I have used tarnation too.
Just “skinflint.” And I’ve tried saying “rumpus room,” but I really think of it more as a den.
Catawampus - actually, we say it “cattywampus” where I’m from, and, yes
Dagnabit - yes (thanks to Yosemite Sam)
Skullduggery - no
Rapscallion - no
Tarnation - yes (another one learned from Yosemite Sam)
Flibbertigibbet - no
Hugger-mugger - no, never heard of it
Absquatulate - ditto
Blotto - no
Hoosegow - no (I prefer “pokey”)
Rumpus - probably, in the phrase “rumpus room”
Skinflint - maybe?
Higgledy-piggledy - no
Piffle - no
Flapdoodle - as in, Bernard J. Flapdoodle, president of the Silly Names Society? 
Lepidopterist - no
No, I don’t think I’ve ever used any of them in a sentence, with the possible exception of “piffle”, which I might have used in a record review.
Catawampus- no, but I’m gonna!
Dagnabit - all the time
Skullduggery- been known to
Rapscallion- more than you’d think
Tarnation- very rarely
Flibbertigibbet- vary rarely
Hugger-mugger- never heard it
Absquatulate- bless you!
Blotto- used to
Hoosegow- on occasion
Rumpus- not so much
Skinflint- no
Higgledy-piggledy- don’t think so, but I like it
Piffle- all the time
Flapdoodle- never
Lepidopterist - you mean as in “my caterpillar got sick so I took it to the lepidopterist?” Um, no.
I use rumpus and keywhumpus (not catawumpus) fairly frequently. I think I got them from the same person from whom I also picked up the frequent use of “swell” and “sweetheart” and “Bob’s your uncle”.
I’m sure I’ve used lepidopterist in context, but there aren’t many synonyms for that.
Yes:
Catawampus
Dagnabit
Rapscallion
Flibbertigibbet
Blotto
Hoosegow
Rumpus
Wow, you’d think I was an old lady or sumfin’. I must watch too much TV to pick up those words like that…
Catawampus NO
Dagnabit NO
Skullduggery YES
Rapscallion NO
Tarnation YES
Flibbertigibbet YES But only if I’m going for a Sound of Music vibe
Hugger-mugger NO
Absquatulate NO
Blotto YES
Hoosegow YES Very often, it’s our common threat to the cat – stop that right now or it’s the hoosegow for you! – nb we don’t actually have a hoosegow nor does the cat ever go to one
Rumpus YES
Skinflint NO
Higgledy-piggledy NO
Piffle NO
Flapdoodle NO, NOW THAT’S JUST SILLY.
Lepidopterist NO
Catawampus - no.
Dagnabit - yes. But not in spoken conversation.
Skullduggery - yes, but ditto.
Rapscallion - yes, but ditto.
Tarnation - yes, but ditto.
Flibbertigibbet - yes, but ditto.
Hugger-mugger - no.
Absquatulate - no.
Blotto - yes. Lots of times.
Hoosegow - no.
Rumpus - yes. “What’s all the rumpus?”, “rumpus room”…
Skinflint - yes
Higgledy-piggledy - yes
Piffle - yes
Flapdoodle - no
Lepidopterist - no
I use none of those words, but I have a friend who uses Flibbertigibbet regularly.
“Yes” to the following:
Dagnabit
Rapscallion
Blotto
Hoosegow (but with a different spelling, oddly enough)
Rumpus
Skinflint
Lepidopterist (used surprisingly often by computer geeks)
I have also never used the phrase “criminal proximity to a keyboard” but I know the concept well.
Catawampus - no
Dagnabit - yes
Skullduggery - no
Rapscallion - yes
Tarnation - yes
Flibbertigibbet - no
Hugger-mugger - no
Absquatulate - no
Blotto - yes
Hoosegow - no
Rumpus - yes
Skinflint - yes
Higgledy-piggledy - no
Piffle - yes (I like saying piffle! It’s just a fun word)
Flapdoodle - no
Lepidopterist - no
I’ve used dagnabit on occasion. I can’t remember using any of the others.
Catawampus (or cattywampus) - Yes
Dagnabit - Yes
Skullduggery - No
Rapscallion - No
Tarnation - No
Flibbertigibbet - No
Hugger-mugger - No
Absquatulate - No
Blotto - Yes
Hoosegow - No
Rumpus - Yes
Skinflint - Yes
Higgledy-piggledy - Yes
Piffle - Yes
Flapdoodle - No
Lepidopterist - No
Cattywampus is one of my mother’s words and, since I’m trying to stop cussing at work, dagnabit gets used a lot.
I’ve often used
Skullduggery
Rapscallion
Tarnation
Blotto
Rumpus
Skinflint
Higgledy-piggledy
Piffle
I say gadnabit instead of dagnabit
I will indever to make use of
Flapdoodle and
Catawampus
in the future, thanks for bringing them to my attention.
Catawampus - No
Dagnabit - Yes
Skullduggery - Yes
Rapscallion - No
Tarnation - Yes
Flibbertigibbet - No
Hugger-mugger - No
Absquatulate - No
Blotto - Yes
Hoosegow - Yes
Rumpus - No
Skinflint - Yes
Higgledy-piggledy - Yes, almost certainly taken from Bloom County
Piffle - No
Flapdoodle - No
Lepidopterist - No