In his 1968 novel Enderby Outside, Anthony Burgess contrived to use the word onions four times in a row:

Then, instead of expensive mouthwash, he had breathed on Hogg-Enderby, bafflingly (for no banquet would serve, because of the known redolence of onions, onions) onions. ‘Onions,’ said Hogg.

Burgess could take playfulness to excess — the first volume of the Enderby quartet got him into a bit of trouble.