
Using Listerine as a cleaning product? When I started playing the saxophone in junior high and on through high school the concept of keeping my sax mouthpieces clean was still a ways off. If you have kids that in junior high and high school bands you should probably check these things out. They are quite gross. Cleaning with something that kills germs and wipes out bacteria is essential. Listerine is a product that can accomplish both.
Consequences

Luckily in all those years I never got sick (that I remember) from not cleaning my mouthpiece. I do know people who have had some issues though. If you happen to have a cold it would be smart to keep your mouthpiece clean. You could keep your cold around much longer than necessary if you are spreading your germs to the mouthpiece, not cleaning it, and using it again the next day. Sad to say that’s what most kids do. If you’re not careful you might give yourself an even worse infection.
Also, if you are prone to fever blisters or cold sores you definitely need to keep your mouthpiece and reed (woodwind instruments) as clean as possible, as you tend to make them worse if you play a lot. Fever blisters and cold sores spread germs and can also be contaminated or made worse by germs and bacteria from the previous day, also increasing the chance for infection. If your lips have any type of tear or any weakness of membranes that are typically a barrier between your immune system and outside germs or bacteria, cleanliness is extremely important. Some infections can even lead to death.
Cleaning it With Listerine

When I did finally realize that I needed to keep my mouthpiece (and my saxophone for that matter) clean I would usually use soap and warm water. However, a friend recently told me that he uses the original Listerine to kill the germs and bacteria in his mouthpiece and on his reeds. Listerine, before it was used as a mouthwash, had many other uses, like soaking your feet, and as a disinfectant (before stronger stuff was discovered). It can kill bacteria. It can help dandruff. Search google and you’ll find a whole host of uses for Listerine.
Finally

On top of all that, there is nothing worse than bringing a saxophone or clarinet mouthpiece to your face and smelling the foul stench of germs and bacteria. Kids do it every day. Some adult players do it too. I have to admit after some of the many Navy parties we played I was too tired and or drunk to care about clean my mouthpiece at the end of the night.
Not anymore. I learned in one of my Culinary Arts classes that as we get older our immune systems are not as resilient. Many older people are susceptible to food borne pathogens. So I am no longer willing to take such chances with food, my mouthpieces, or anything else.
It only takes like two minutes of soaking the mouthpiece in the Listerine. Wipe it clean with a clean rag, then, rinse with warm water (unless you like the smell of Listerine), then dry. Nothing to it. At the very least you can soak the tip of a clean cloth or paper towel in Listerine and wipe your mouthpiece. The mouthpiece is clean. It smells clean, and you don’t need to worry about germs and bacteria when you play the next day. It is especially important to clean your mouthpieces if you have a cold or are sick in any way. And, it’s just good hygiene.