Use Automator to create a service that runs this applescript
set myVol to output volume of (get volume settings)
set volume 0
set volume (myVol / 14.5)
Then in System Prefs in Keyboard > Keyboard shortcuts add a shortcut to the service.
Done. 15 sec delay to volume which does most pandora ads, not enough, hit it again... never hear about 5 hour energy again.
Don't ask me why you have to divide the volume by 14.5 but if you don't it gets incrementally higher every time....