Has anyone heard about anything, or thought of anything that might work to deflate one of these, at least a bit?
Not a hurricane expert here, by any stretch.
I'm guessing you're thinking nukes, since a conventional weapon would be as effective as flatulence in a windstorm. My understanding is that the last thing you want to do to a tropical cyclonic storm is add more heat to it. No that's next to last. Injecting radioactive debris into the storm is the last thing you'd want to do.
The scale of these things is such that even one of the old, huge 20MT Soviet weapons designed to overcome inaccuracy of delivery with raw power and destroy whole metropolitan areas would just be a little blip in the face of a major storm.
If you could find a way to chill ocean water in it's path on a grand scale in a short amount of time, you might have something to work with.
Check out 1947 dry icing(silver Iodide ) of hurricane in Sept./Oct.
Was supposed to cause storm to lose power. Caused SEVERE flooding of South Florida! Ft. Lauderdale to Miami under water.