I also feel that there maybe a possibility my cham may be developing a RI. When I had feed him I hear him inhale and it sounds raspy and somewhat phlegmmy . I have never seen any bubbles or anything like you are dealing with, he just sounds slightly congested.
I ordered my cham from Chams Northwest and also bought a bottle of Rept-Aid. As of today I am on day 3 of the 22 day regiment. I have yet to find some solid factual info regarding Rept-Aid in the treatment of an RI, weather or not it is capable of completely eliminating the infection or more of an organic placebo. There have been a few posts I remember of forum members using Rept-Aid as a booster but unless you take your cham to a vet for diagnosis you can never really tell if A.) Your chameleon does indeed have a RI. or B.) A dosing regiment of Rept-Aid is called for.
Using it as a booster 2-3 times a month for a healthy cham is way different than the 22 day plan laid out in the instructions, but hey. It still is way better for the chams system than some Baytril