I have encountered this in the past. It is often from poor sanitation (dirty water dish) but can also be from airborne pathogens. The puss pocket needs to be opened and scraped clean. The puss isn't normal puss like you or I would get but rather is a hard cheesy type of substance.
The mouthwash will be very hard to use with a MHD and sometimes this condition is from systemic infection, i.e., carried through the blood stream. If you treat the mouth but not the source her chance is not good. If you can convince your vet to put her on oral antibiotics she has a good chance of recovery. Some animals don't pull through it as well as others and seem to have recurrences even after successful treatment while others clear up and never seem to be bothered again.
I am surprised that your vet didn’t scrape the pocket clean for you. Some vets will only do this as a surgical procedure but I have cleaned these myself and although it’s a real job it can be done at home. You have to be very careful and thorough and make sure you keep everything very clean. I use alcohol to clean the tools and make sure you wash really well after handling anything.
I really doubt her odds are good without the oral antibiotics though so I would give the vet a call to see what he says.
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Marcia - FroggieB Dragons
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