Do you have any papers or studies showing it can reduce transmission of any disease? Covid lives in the throat and lungs so I am not sure how a mouth rinse could do anything. Similarly for many other common colds and the flu.
I did a quick search and there are numerous studies that come up. I haven’t analyzed them myself, but it seems like there is a lot of evidence for this (example https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8956107/). I also found various things written about covid living in the mouth and playing a role in transmission.
