Most people don’t realize this, but any mirror maze — you know, one of those amusements where you have to navigate a maze made out of mirrors and clear panes of glass — is also an interdimensional portal. Every time someone goes into one, they come out in another universe. Infallibly.
And the reason why most people don’t realize this is because, for all practical purposes, the universe they go to is identical to the one that they left behind. When it comes to alternate timelines, people concentrate on the universes where there were big changes, like battles having different outcomes, or asteroids hitting the earth. Little changes, such as atoms moving slightly differently, are far more common, albeit typically not very long in duration. The micro-universes thrown off by these lesser changes usually recombine pretty quickly, so nobody really notices.
However, someone who uses a mirror maze does actually jump from one dimension to another. It may not be for very far, but it’s far enough to break any sort of tracking or scrying spell placed on that person. Or, in fact, the link between that person and a voodoo doll. And the effect also does not last for very long (typically, an hour or so). But sometimes an hour is just enough time to do something.
Note that mirror mazes do nothing to throw off purely mundane tracking. I mean, obviously.