The competition is a crock, they all are. The best way to deal with it is not to take them seriously and eventually they will fade away. Its just an easy little publicity thing for the dubbing company to do, and while a role in an anime may mean a whole lot to a lot of people, a quick one-off character really doesn't mean much to the people directing the anime.
Personally, I just avoid these things like the plague. Tried it once, and I have no intent to do it again.