Avi, don't post trick or treat anymore on their profiles. =O That part is over.
Right now you should just send an empty trade (as stated in the first post) to Vicky, Mr. Mayor, and Aimee~ :'D <3<3 And then just wait for them to add the item and accept the trade. More NPCs may do this later on, but for now only the above three have agreed to hand out candies this way. ^^