So, if I drink my mouthwash straight from the bottle, and it sits on the counter in the bathroom all day for the length of time it takes for me to finish it… is my backwash germs instantly killed? Is the mouthwash going to get funky after a while?
Eventually, the germ-killing power of the mouthwash will be eaten away from killing the germs which you keep adding to it. So, yes, evenutally it will go septic. (funky).
It’ll last longer if you don’t spit it back into the bottle.