Xylitol worked well for me.....once! It caused total break up of the biofilm which made me very ill coughing up stomach acid burning my throat.
It never worked after that.
I am not sure that it helps penetration of the biofilm, I think it gets used by the bacterial to produce the biofilm but is unstable and breaks up. That would explain my experiences with it but they must adapt and stop using it making it useless after that. It has never done anything since.
Xylitol can cause diarrhea. Erythritol is another sweetener, which does not adversely affect the bowel like Xylitol, but it has never done anything in my experience of trying it.
I wonder whether it must be combined with stressing the biofilm ie enzymes to cause degradation in order to force take up of the sweetener. I am not sure why it worked the way it did for me. I was on the GAPS diet at the time taking bone broth and a number of culinary herbs. One day I added Xylitol to it and the following morning before I had eaten my stomach started producing enormous amount of acid, like the breaks had come off my stomach acid production! Coughing up stomach acid and I felt so ill. Something must of contributed to it, maybe a combination of things that worked together perfectly which I have never been able to reproduce again.