When referring to a cure for robbing Dave said, "Plug the hive up tight, or
put it into a place not accessible by bees. After a few days, the robbers
will forget about it."

Personally dubious whether they "will forget about it". My own method would
be to removed the majority of the comb and stores, leaving just one frame
containing little honey. Leave them to complete their dastardly deed and
hopefully they will retire satisfied (and then forget about it).

Ken Hoare