Trashcan's goal is to emulate the modded items called 'trashcans' with you all your junk items can simply be thrown into and will cease to exist. You simply rename a chest (also works with trapped chests and barrels) to whatever is set in your config.yml, which by default is 'Trashcan' and off you go.
Items can be deleted in one of two ways.
1. You manually put items into the chest and when you close it, after a configurable time delay, the items will be deleted.
2. When a hopper puts items into it they will be immediately deleted.