"Just caught her! She says she'll get the Cleansweep if she can."
-- Ron Weasley (OP9)
The Cleansweep Broom Company, started in 1926 by Bob, Bill and Barnaby Ollerton, produces a series of sport broomsticks.
Features
The Ollerton brothers produced large numbers of Cleansweeps aimed specifically at the racing and Quidditch markets. Models released by the company include: Cleansweep 1, Cleansweep 2, Cleansweep 3, Cleansweep 5, Cleansweep 6, Cleansweep 7 and Cleansweep 11 (QA9, CS7, OP9).
The Cleansweep series are known for their ability to turn corners quickly and efficiently (QA9).
Madam Hooch notes that Cleansweeps have thicker handles than a Firebolt when examining Harry’s new broom (PA13).
Appearances
Fred and George Weasley fly Cleansweep Five brooms (CS7).
The Ravenclaw team is said to have the latest model Cleansweep brooms in Harry’s third year (although in the next chapter their Seeker Cho Chang is actually flying a Comet 260) (PA12, PA13).
Ron Weasley gets a new Cleansweep Eleven broom in his fifth year, as a reward for becoming a prefect (OP9).
In an article published in The Quibbler, a wizard claimed to have flown to the moon on a Cleansweep broom (OP10).
A Cleansweep broom ridden by Holyhead Harpies captain Gwendolyn Morgan, featured in one of the finest Quidditch games ever seen in 1953 (QA7).
Two Cleansweeps ended up in the River Mersey when rushing to get to the last of Celestina Warbeck‘s Flighty Aphrodite concerts (DP2, Pm).
Splinter and Kreek‘s sells secondhand Cleansweep brooms (DP4).
Commentary
Etymology
In popular use, a "clean sweep" is a complete win over the opposition - sweeping the board clean.
Notes
Lexicon list of Broom Manufacturers 
Although the dates printed on the Daily Prophet Newsletters are:
the timeframe for these events is 1992-1993.
From the Web
Pottermore features:
Harry Potter Wiki:
Pensieve (Comments)
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