This will show its BS.
Hmmmm, dont we all breath in the same air that goe's in a sryange?
Also mythbusters did a thing on Bacteria on a toothbrush right next to your toirlet.
And guess what, NUTHING Happened!!!!! There was just as much/little Bacteria on the one brush locked away, as the one brush right next to the toirlet So, there goes your Bacteria theory! period.
Peace Out.