I've tried this technique, and I found it doesn't work... At least for me... I don't take too much time to get "in the zone" but when I am, I don't want to break that for a small break, I'd rather keep going until I lose focus or something.

Say if one day I'm extra unmotivated and it takes me 20 minutes to get into it and I start this timer, stare at my code, tinkering with small things, like indentation, or something that really doesn't matter, then I finally get into it and start doing something productive, 5 minutes passes and I need to "take a short break" which then causes me to lose focus... Then I'm right back at phase one... I prefer to either just force myself into the zone, or let myself get to the point on my own... Then stay there, not stop.

Like Thursday I had no motivation or anything, sat at my computer screwing around from 8AM until 2PM when I finally started being productive.... But then there's days like Friday and yesterday where I jumped out of bed and was productive until I had to force myself to bed at 2AM.