Natural consequences doesn't mean "law of the jungle" here. It just means linking cause and effect in a proportionate manner.
I tend to use a lot of "natural consequence parenting". Basically, the response should flow from the cause. If you throw water over your friend, you can't then complain if they throw water over you. You learn that, while it's fun when expected, it can be deeply unpleasant when unexpected.
It's a lot more effective than random generic punishments. The trick is shielding them from excessive results, while allowing proportional ones to play out. E.g. swinging on a chair will get a warning, but often not stopped. When they fall, there's an "I told you so" before/with the cuddle. If there is a risk of a more serious injury however, e.g. the corner of a table where their head may hit, then I step in and stop things.