If you are running KDE and if you have a Wastebin widget on the desktop or on the panel, you can empty it manually by right-clicking the icon and choosing "Empty Wastebin".
If you are running Dolphin you can right-click the "Wastebin" entry on the Places panel and do the same thing. In Konqueror you can do the same thing, or you can type trash:/ in the address bar, hit enter, and then right-click the window that is opened.
(Or you can empty your Wastebin directories one by one....)