Old School Justice

If you’re going to do this, you might as well do it right. The tar and feather combo is a classic for a reason – it’s effective, and it takes forever to clean off.

You rig up a bucket of roofing tar above the door, perfectly balanced so that opening the door triggers the dump. Below that, you’ve positioned bags of pillow feathers to complete the look.

It’s like something out of a cartoon, which means it’s probably going to work perfectly. Now you just need to wait for your unsuspecting victims to trigger your masterpiece.