See how he gets on. If he does start to show a reaction to the salt, do a water change to remove some of the salt straight away.
I see. I figured the epsom salt baths would help with the dropsy but conflicted on its effectiveness. The scales were raised but never pineconing however I did notice he didnt look bloated anymore or at least the bloating went down. If there anyway we can catch signs of this underlying disease before it escalates? The fuzz was so stubborn with all the meds I used I fear it tainted the tank. Im open to do a mini autopsy on betta if it helps get answers.I doubt the fuzz was the cause of death. There was probably something else going on which meant he was more likely to pick up secondary infections such as the fuzz which was growing on him.
I agree with @Lcc86 - if he had dropsy, that is another symptom of an underlying disease. Dropsy occurs when the fish's kidneys start to fail due to the underlying disease. Once the underlying disease reaches this stage, it's usually just a matter of time no matter what we try to treat it with.