Well, I don’t know that this is “effective”… or wise. But I’ll tell you how a friend of mine did it. Names changed, etc.

John was at home, minding his own business… and his girlfriend of 5 years comes home. Stomps in, drops her stuff… and without further introduction, looks at John and says “Oh, YOU’RE home… I don’t even want to look at you right now”.

John, caught completely by surprise, fumbles out “What are you mad about?”.

The seething reply was “Oh, YOU KNOW what I’m mad about!”… and she storms off into the bedroom and slams the door.

So, John sits there, blinks a few times… then gets up and goes outside.

Now we switch scenes to inside the bedroom where Megan sits on the bed… mad at John for reasons unknown… but VERY mad.

The bedroom door opens… and there stands John, with the garden hose in his hand.

He lets loose with a good 5–6 second blast of water from the hose… liberally soaking Megan, the bed, the bedroom, pets, whatever… He shuts off the hose nozzle, looks her right in the eye with a big boy scout grin John is known for… and says, almost proudly…

“NOW, I know what you’re mad about!”.

Folks, that is the sort of exchange that really can only end with two sounds… laughter or a gunshot…

The neighbors declined to call the police over the loud laughter heard.

Any time either one of them retells this story, neither of them can remember what she was ACTUALLY mad about.

https://www.quora.com/What-is-the-most-effective-way-to-stop-a-fight-in-a-relationship/answer/Paul-Feist-1