Out of about 7 CBB's I've had over the years, each ate different things, couple did not eat, 2 were awesome and ate apt and prep'd foods and no corals, so it's pretty random, and the 2 that were awesome were Ausies, which my LFS swears by.
Our local club passes a couple file fish around, but they get snatched up quick, so I figure if mine goes bad after eating apt I'll just add him to that list for someone else to use, at least it should be fairly easy to catch.
Mine is super easy to catch . Likes to hang out in the top corners of the tank and sleep sometimes. I can reach in and touch her or him . Catching in a Container would be super easy. So for my CBB has been a model citizen. It was super tiny when we got it a few years back and is now maybe 4 inches and Fat as a pig eating anything we put in the tank as well scavenge For pods..