Tongue Scraping vs. Brushing Your Tongue: Which Is Better?
Tongue scraping and brushing your tongue both help, but a scraper is generally more effective at clearing the soft film that builds up on the tongue's surface. A toothbrush is designed for teeth — its bristles tend to move the film around rather than lift it off, and the brush shape doesn't match the broad, flat surface of the tongue.
A scraper, drawn from back to front in a single pull, clears that layer in one motion and tends to reach further back, where most of the odor-causing buildup sits. If a scraper is what you have, great; if not, brushing the tongue is still better than nothing. Many people do both — scrape first, then a light brush. More in why scrape your tongue.
Try a Dentō tongue scraper.