My experience with chum at destonation fisheries.--- They are not in a feeding mood. Almost all if not all are snaged or lined in the mouth. If you wish to catch them in the mouth, fly fishing is the best bet. Cast in front of moving schools but don't jerk or set the hook, let the fish tell you with his own reaction. Lift the rod only when there is a solid strong pull.
Sorry to inform you that luring them to bite is next to impossible but hooking them in the mouth is very possible with the right teck.