That is what was stated on the show, anyway. I think he meant mouthwash is used to eliminate the overgrowth of bad bacteria. I mean people use it for bad breath, which is an overgrowth of bad bacteria. It is my guess that the mouthwash targets the overgrowth of bad bacteria, but when you use it too often it also gets the good bacteria. But, I do not know exactly the reasoning behind it. There are probiotics formulated for the mouth if others are worried the bacteria balance is off. I recall someone writing that maybe a bacteria transplant would be helpful, but mouth probiotics may be an easier option. This strain of yeast has never been in the probiotics I bought. It may need to purchased separately. It is probably a good choice for candida in mouth. It reversed celiac disease in mice as well.

http://www.ncbi.nlm.nih.gov/pubmed/20629753

I do not use mouthwash either. From time to time, I just gargle with salt water or baking soda mixed in a glass of water.