Mouthwash, oral cancer, and distilled essence of rotten

Alcohol, or distilled essence of rotten (you must say it in an elegant and sophisticated accent), is known as a great sterilizer i.e. purifier, in our contemporary world.  In many places around the globe people do not feel the need to wash one’s hands with water after using the bathroom, when one can just squirt of foamy alcohol hand sanitizer.  However I always remember a class wherein Srila Prabhupada states that it does not purify but rather makes things impure.   Recent oral cancer studies had given some new insight.  But first here is an except by Srila Prabhupada. 

So the Vedic conception is completely different. The… According to modern science, they put things into alcohol to sterilize. Is it not?

Svarupa Damodara: Put alcohol in things.

Prabhupada: Yes. But it becomes more impure. Anything you put into alcohol, that becomes more impure, according to this.

>>> Ref. VedaBase => Srimad-Bhagavatam 1.8.52 — May 14, 1973, Los Angeles

In the study done by Leibniz Institute for Prevention Research and Epidemiology with assistance from Glasgow University’s Dental School it is revealed that not only does poor hygiene contribute to cancer risk but also regular use of mouthwashes that contain alcohol.  
     The NPR article can be found here.

It is interesting to note that is found that other intoxicating substances such as tobacco and betel nut contribute to risk of oral cancer. 

Just as impure things cannot truly clean similarly it is stated that hearing kirtan of the Holy Names of Krishna or about Krishna from those who have no faith that Krishna is God cannot purify us in any way and can in fact sometimes be detrimental to our spiritual growth.  The old adage is that milk, although nutritious, when drunk by a serpent becomes poisonous.