I use certain videogames for something similar. I've collected a bunch of (Nintendo DS, generally) games that I can play for five minutes or so to pretty much reset my mind. Mostly it's something I use for emotions, but the basic idea is to focus on something that takes up all of that kind of attention - that fully focuses that part of my brain which gets stuck on things.

Key to this was finding games that took all my attention while playing, but had an easy stopping point after five minutes or so of play - Game Center CX / Retro Game Challenge is my go-to, with arcade style gameplay where a win or loss comes up fairly quick.