Natural mouthwash - suggestions please

Does anyone make their own mouthwash? I don't use it, but my other half does, and I'd like to be able to make him something less synthetic and nasty!
Maybe something with antibacterial herbs? But don't we have friendly bacteria in the mouth too?

My partner makes a magical herbal mouthwash that solved my serious periodontal issues!  They were ready to do surgery and what all else, but the last time I went they asked me what I was doing and said keep doing that!  
The gist of it is good handfuls each of rosemary, thyme, calendula, echinacea, white oak bark or acorn meal, and smaller amounts of stevia, cayenne, and cinnamon.  Simmer all in a big pot of water for half hour or so and let cool.  Strain and mix with 30% minimum of strong alcohol (gin or vodka) and it will store at room temperature.  To use without adding alcohol, freeze in small containers, and thaw them at need and keep refrigerated.