Not sure about this. Probably better to add some chelating agent to the distilled water.
At some point the excess minerals in the media will be locked up and things should get better.
Likely not a good idea to bring in the tree if you have a/c. That would cause a whole slew of issues…light. humidity, acclimation both taking the tree both in and out later... Usually azaleas respond in a two to four week window when conditions change to the positive…
Is it possible to move the tree to more shade and water down the ground underneath, mist and wrap a wet towel around the pot to keep the media cooler… and make sure the foliage dries before sun down… or is this something you have done already?.
Cheers
DSD sends