rinsing with a dilute bleach solution is a good idea occasionally, regardless. if you drink from the bottle directly you will contaminate the liquid from your mouth, lips, saliva and it will get slimy and eventually moldy. hot soapy water with just a spoonful of bleach will clean it.
then rinse very well, let air dry after draining upside down for a while. I store the bottles with lids off so they don't grow things if accidentally stored while still damp.
Bleach is dirt cheap and useful for a lot of things.
"If the world were a logical place, men would ride side saddle." Rita Mae Brown