I've heard of doing this before, but a local reefer with a well known tank recently posted some photos and results of changing over to a xenia scrubbing refugium. Thought you guys might enjoy the link. Once I get my light fixed for the fuge I'm consider trying this as well.
http://kipsreef.com/forum/showthread.php?t=654
http://kipsreef.com/forum/showthread.php?t=654