mouth rot

My beardie's teeth have a buildup of brown and I want to try what I can at home before taking him to the vet (if it was urgent I definitely would). I'd like to try out chlorhexidine because that sounds like a good potential solution, but I'm so confused on which one to use. I'd rather not get...

I have a male bearded dragon (he's around three yo), and I recently discovered he has mouth rot by looking inside of his mouth with a Q-tip. I have been rinsing it with betadine and water, administering vitamins and probiotics, and I have even been using rot guard, but it's not getting better...