I am trying to remove a stuck shower fixture -- photo below. This fixture has two handles (bottom for temperature, top for shower/wand selector).
I was able to remove the bottom handle using strategies I described here, but that hasn't worked for the top handle yet. I'm confident I have the set screw loosened enough for the top handle, but it's still not budging.
I'm assuming there are mineral deposits in the top handle where the cartridge meets the handle (like there were for the bottom handle), but I haven't found a good way to get vinegar squirted inside there yet. Any thoughts or ideas would be greatly appreciated...