The first one I had succumbed to an infection very quickly before I could treat it in the QT, one day it showed the first signs of an infection the next day he was dead. With the second one I didn't take any chances and started antibiotics as soon as I put him into the QT, followed by the usual course. Look the CBB over very carefully at the LFS and make sure it's eating.
I feed my fish nothing but live Black Worms and frozen foods, no flakes, pellets or processed foods. While in QT I started feeding him the same things I feed my other fish. He took to everything but favors live Black Worms and BS the most, but will pick at Mysis, LRS and clams. If you can get live Black Worms do it, mine goes absolutely nuts for them. He'll swim back and forth and do head shakes when I'm approaching the tank to feed, it's like he's telling me to hurry up. He eats them as they come out of the eye dropper as I squeeze.
I didn't get my CBB for Aptasia control, I just love the fish, but I've been lucky and mine does eat Aptasia. I didn't have an infestation but I would get some Aptasia here and there. After getting the CBB there are no more Aptasia on the rocks like before, the only ones I'm finding now are the ones deep inside crevices that the CBB can't get to, so I take care of them with the Aptasia-X. I would take time during WC's to go around with the Aptasia-X killing those suckers, not anymore, now just when I find the rogue Aptasia that CBB couldn't get to.