if someone is as clean as a whistle, they are not involved in anything illegal.
He hasn't got a criminal record - he's clean as a whistle.
2.
to be very clean.
The café's as clean as a whistle, and the food's excellent.
(redirected from be as clean as a whistle)
be (as) clean as a whistle
1. To be neat and tidy in appearance. This house needs to be as clean as a whistle before my mother-in-law gets here.
2. To be well-behaved and not involved in illegal or questionable activities. You can trust George, he's a good kid—as clean as a whistle.I don't have a criminal record, I'm clean as a whistle.