when you shook them out, you let them return to the same hive? laying workers fly. they would fly back to the hive, the hive would believe it still had a queen, and would kill the new one. when you shake out a hive, you need to take away the old hive and let the workers join your other hives.
you can try requeening, but it's better done with a push cage than just hanging the queen cage in the hive. you can try putting a fresh frame of eggs in the hive every few days until they make a new queen.
the easiest thing to do is shake them out, but do not give them the original hive. let them fly back and join other hives. take the old hive across the field, take an extra empty box and a towel. as you clear each frame put it in the empty box and cover. when you are done, put all the stuff away so the bees have nothing old to attract them.http://www.bushfarms.com/beeslayingworkers.htm
simple instructions and ideas.