A proper venting process, like a heatsink or coolant, needs a mechanism to absorb the unwanted energy efficiently, and then disperse it. Asking folks to express anger or spend energy without it specifically drawing from the negative emotions within is like pouring coolant fluid from a bottle over your CPU box.

I think carefully channelled energy, however, can really help calm. I don't necessarily think it's catharsis really, as it would tend closer to meditation. Practising a martial art, trying to focus on something creative, going on a long run, playing a mentally demanding game (chess, go, starcraft) — with the right mindset, these allow you to harness your negative feelings into an activity that exists in its own sandbox, and then get processed in a way that only makes sense inside that sandbox. It's important that your activity is one where you have practised not getting further enraged (no 'tilting', as we say in video games) when you fail/perform badly inside your sandbox.

When you leave the sandbox, you find a tiny bit more peace with whatever enraged you.