Rinse with warm salt water: take a sip, then raise your head and shout "ah ~ ~ ~". That's it, rinse your mouth 1 minute or so, spit it out, and then take a second sip ... It will be much more comfortable to rinse your mouth several times, and then rinse your mouth with salt-free warm water once, and it will be fine.

Salt water itself has the function of sterilization and itching relief.