I think it might be too small and itw ill float to the bottom and foul up your water. My bettas can barely eat Freeze dried daphnia, and it's bigger, so, I dunno.
Yeah, I don't feed my adults bbs regularly or as part of their general diet..but if I have extra left over, I put them in their tanks. And they usually eat them. But my fish are PIGS! LOL And, yes, they eat left over microworms, too.