Okay. Surely, the stock bottle would be deactivated by the air particles as well. What would be the difference between the stock bottle and a cleaner bottle filled with distilled (not tap) H20 in this regard?

I have two bottles, one I replace every week (after hearing about the life expectancy), and one that is several months old (used very rarely as a control). To date, I have not noticed any difference between the two. I don't expect to though if just the viricide and bactericide efficacy decreased.

I'll still change my regular use bottle once a week to be safe but would really like to hear more info on this if there's any out there.