I wouldn't encourage any fish to eat mussels or clams. That is if you want to keep any in your system.
I QT'd my CBB in an established QT tank with rock from my display sporting aiptasia. I did NOT feed it anything while it was in the QT for 4 weeks. How's that for counter-culture??
Anyway, I had thousands (yes that's right) aiptasia in my display, and a billion feather worms. Once I was satisfied that the CBB was very healthy and would eat aiptasia, I released it into the display at night. This fish was quite skittish in QT, darting around like a maniac. Once in the display, within 24 hours it was hanging with the tangs and wrasses, hunting among the rocks, and to this day is on an ever present search for tidbits in the rock. It also is getting interested in what i feed the other fish, and has joined the feeding pack. I am not sure if it has or will eat the prepared food, but since I have a never-ending supply of aiptasia, I think I am OK. If I feel that it is going hungry, I will trade it off to another reefer.