I think its the alcohol in listerine which makes your mouth sting, which is actually *good* for your mouth, but it makes you think its working. Just like someone has said with the dentyl one, the gunk you see when you have used it just makes you think its working, its not really much better or mowrse than one which doesn't do that. Tbh, there are going to be good and bad things with all of them, I normally just use one which doesn't taste too foul and leaves my mouth feeling fresh but not like I have just removed half my cheek lining!!