clean as a whistle

Idioms  

1. Completely, entirely, thoroughly, as in He chopped off the branch, clean as a whistle. The allusion in this simile is unclear. It may have been a replacement for the 18th-century clear as a whistle, which alluded to the pure, clean sound of a whistle (it has few overtones). However, it was adopted to describe something thoroughly done. [Early 1800s]

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Example Sentences

After escaping a pair of masked assailants, he brings the police around; the sauna, you will have guessed, is clean as a whistle.

From Los Angeles Times • Nov. 28, 2024

When I come to, I’m in the recovery room, head still cloudy, soul unsettled but clean as a whistle.

From New York Times • May 13, 2022

I searched online how best to get that area clean as a whistle with no viable results.

From Slate • Feb. 16, 2021

So short of actually poking your head into the kitchen, how can you tell if a restaurant is clean as a whistle - or no such thing?

From BBC • Apr. 24, 2016

The stone knocked Merlyn’s hat off as clean as a whistle, and the old gentleman chased him featly down the stairs, waving his wand of lignum vitae.

From "The Once and Future King" by T. H. White