TIL that you are not supposed to rinse your mouth with water after brushing teeth or using a mouthwash, because the fluoride coating on your teeth helps protect against cavities and rinsing your mouth after dilutes the fluoride, making it ineffective. Instead, you should wait, preferably 20 minutes.
https://www.sensodyne.com/en-us/oral-health-tips/should-you-rinse-after-brushing/