UTI is a total different situations,the respiratory and the bone disease are what I meant with the mouth rot part if it gets worst ,I believe the dosage on the symptoms between the UTI and the symptoms with ur chameleon right now could be different,I would consult ur current vet before u give him the Baytril.
Regarding the Listerine(mouth washer) what I did on mine for periodically prevention is 8qtips along with diluted solution of the mouth washer 1qtip on the upper part inside n 1 for the bottom ,same for the other side, then I repeat with just plain warm water to do the final rinse just to take away the left over in between 5 to 10 min ,so the cham has few min to let the mouth wash do the works before completely rinse off and so far all mine is healthy on their mouth part,I dont feed them anything has large sharp legs and I gutload n supplements them with the correct recommendations.