Tired of reading spaghetti code written by your team mates?

Sit right next to them and ask them to write unit tests for that code.

Smash their head on the keyboard everytime they have to think longer than 10 seconds on how to test a specific logic.

Strangle them with any wire you find nearby till they agree to break up that spaghetti code unless they already started within that 10 second time frame.

When the exercise ends, tell them this is what refactoring is and ask them to pass on the knowledge.