A replacement for a 'blue' word by another non-rhyming word, could be, by analogy with an interrupted cadence in music, an interrupted rhyme.
An actual rhyme, or a change of context in order to put the rhyming word into an innocent-sounding phrase, such as the 'cocktail' example above would be covered by the more general context of inuendo, since there is nothing special about the rhyme itself.
Cheers
Dave