The regular brown colored Listerine is the one you want-you can just dilute it with water.
Here are some other reptile related uses for Listerine-
We use it to clean cages and it works great and smells good.
We use it for cleaning the snakes skin when they lay in urine or blood or just to get the smell of food off of them.
We have used it for cleaning rubs or scrapes from escapes/attempts.
We have used it on the thin film on the mouth around lips that goes along with an RI,
when an RI is present we use to clean mucus out of mouth and to keep bacteria from growing in the mouth.
Cleaning a cage after female has laid and to clean the female with to rid them both of the smell of the eggs.
Our big girl took a rabbit and after she had finished she was fixing her jaw and opened real wide we noticed a cut I guess from a rabbit claw; for 5 days I cleaned the cut twice a day on the 7th day she was ready to eat again.
Also it is right up there with alcohol and warm water to make the snake release if it is latched to you and then you can cleanse your wounds afterwards.