Gargle

[Couch Potatoe]

To wash or rinse, as the mouth or throat, particular the
latter, agitating the liquid (water or a medicinal preparation) by an
expulsion of air from the lungs.

[Britney]

to move a liquid around in your throat without swallowing, especially to clean it or stop it feeling painful

[Oralee]

Wash ones mouth and throat with a liquid kept in motion by exhaling through it.