Do "relationship timeouts" ever really work?

I was talking to a girlfriend of mine the other day. She said she and her man have been verbally sparring and generally not vibing lately. They've been together for about three years, not married yet and things are getting a little choppy. It's clearly past time for everyone to put their cards on the table and see who is all in. Instead, they decided that what they need is a little break from one and other. She asked, "Do you think it will work?" And by work, she meant did I think that the two of them being apart for a while would eventually bring them closer together. Well, let's talk about this for a minute.

I'm not sure I understand relationship breaks. I've tried this twice and both times at the end of the "break" period we were done. In my cases, the break was really just a prelude to the break up. Sometimes a break is a chance to get the other person used to the idea of being without you. It's a relationship purgatory, if you will, where eventually you go to the happy place or the unhappy place. Sometimes it's a wake-up call. But mostly (in my experience) it's a stopgap because neither party is completely ready to pull the plug or stay together. It's an uncomfortable place to be. 

Another complicated thing about breaks - what are the rules? Are you still seeing each other, are you seeing other people? Do you talk, text, tweet? Are you going to share what happened on the break with each other after the break is over? Does what happened on the break, stay on the break? How long is the break? Do both parties have to agree to the break? Is it like a performance improvement plan and there are things that need to be upgraded prior to continuing? 

Then again, there are definitely times in a relationship when you want to throw a flag on the play and penalize somebody. At that time, it's best to separate the players until things cool down. Maybe a break is an opportunity to step back and gain perspective? Or an opportunity to miss the water when the well runs dry? Or the chance for the mice to play while the cat is away? Once I start typing in metaphors, it's time to move on. 

To me, once you get to the point in a relationship where you feel you need a physical and mental break - that's problematic. But does problematic necessarily mean catastrophic? The best advice I could give her was to put some clear cut parameters around the break. Set a time frame and rules of engagement. Have some sort of plan in place for after the break. If everything is going to be just the same as it was before the break, what's the point? 

What I'm asking, BougieLand - what are your thoughts on relationship breaks? Have you done this? How did it go? Do we know of any that resulted in the couple getting back together and working it out? Please share...