Another Thunderbird Extension

I just found another very useful Thunderbird extension: Empty Trash Toolbar Button.
Install it, restart Thunderbird, right-click on your toolbar to Customize, drage the new Trash icon up to where you want it, ok. Now, to empty the trash, just click on that button.

To empty your junk folder, there is a Delete Junk icon already in there (when you Customize the toolbar) - you can drag it up to where you want it to have a shortcut for that too.