Actually I did know xD For once. I figured early on that using a mouthwash with a drying effect will obviously leave your teeth defenceless against any new bacteria. Even worse if you happen to be a mouth breather. And as you say the same logic can be applied to anything else that kills off bacteria. Rinsing after using mouthwash has certainly improved the whole drying-mouth thing since I started recently, although heaven knows what the water leaves behind and I still get the benefits of the mouthwash, its a difficult decision to make tbh as both sides (ie not brushing and brushing) have their bad points.
In this day and age everything that we use is so chemical and man-made you would probably find we would have a much better life if we just switched to how we were intended to use things to keep our teeth clean, things like fruits etc... But that's debatable.
Out of pure interest what would you suggest is removed or limited from the daily routine to minimalise 'health problems'? Things such as daily showers etc...