How did they get away with it when it so obviously just another word for f**k?
Because there's no rule against using substitute words.
Red Dwarf made up 'Smeg' which they used in place of pretty much every other expletive.
Recess made up the word 'whomp'. Which if I recall correctly, the kids in the school made it up, but then when the principle found out it was a fake curse word he tried to make them stop using it.
Spongebob makes up a bunch of them. 'Halibut' in place of 'hell'. 'Barnacles' in place of various other words.
Friendship is Magic uses 'hay' instead of 'hell'
The whole idea of vulgar words is pretty silly when you give it any kind of thought.
I don't know who the halibut shoud give a smeg about some frakking fake swear words when the whole fucking idea of 'offensive words' is a whomping load of barnacles.