[One, Two, Middlesboogie]

I think you're missing the point here, Max. This topic isn't just about slang words for other slang words, it's also about slang words for ordinary words.

Another one my family and I use regularly (almost totally in place of the real words, in fact):
Weewus - Snail or Walrus.

You can only tell which one (snail or walrus) we're talking about by context alone. It does seem odd to have the same word for two totally different animals, I know, but the French use the word 'chouette' to mean either 'screech owl' or 'nice'.