To check if you have bad breath, you can lick the inside of your wrist and smell it after a few seconds; if your breath is heavy, cleaning your tongue can help eliminate odor-causing deposits, though this does not replace a comprehensive evaluation by a specialist.

noli's read

Regular tongue cleaning to freshen breath is based on solid scientific evidence. A systematic review by the Cochrane collaboration confirms that using a tongue scraper or brush helps temporarily reduce the accumulation of deposits on the tongue and associated odors. However, the 'wrist test' suggested is a very rough indicator. While this method is sometimes mentioned in reference guides, such as those from the UK-based Oral Health Foundation, it lacks scientific rigor. This technique only captures saliva from the tip of the tongue, whereas the majority of odor-causing deposits are lodged at the very back of the mouth. This test can therefore generate false alarms or, conversely, miss actual discomfort.

the sources

No named source held this one up — that absence is part of the verdict.