These are both Clean Boomerangs (with the ball rolling out >10 minutes- so not a true Boomerang Champion)
Mine is in the construction area a little longer, but MrZNF's is a lot less pieces.
Meantime, there's no Clean Champion that I know of.
malisp put this http://fantasticcontraption.com/?designId=512918 in the Clean Challenge a month ago, and I'm pretty sure it worked then, but it doesn't work for me now. Maybe a physics change did it in.