I can actually, perhaps, extend the form to 12 lines with 'forever loop', 'slurp', 'pillar', 'water polo' and anything else that crops up in idle moments and one can see how the search for rhyme can lead one to outlandish ideas that would never have happened without the discipline. Although we must use them in subtle ways and not be seen to be crowbarring them in.
Another poem to take is Ted Hughes' October Dawn that is half-rhymes throughout before rounding off on a full rhyme.
Ripple
Some poets regard rhyme as puerile,
something they need to withstand or repel
unlike Chaucer in his undemure pool
of couplets that he begins in April.
But somewhere in this short downward spiral
it might lurk disguised, keen to explore
in the same way that many people are.
Thus rhyme is a gentle interloper.
