deviled eggs glow greenish. if you put slices olives and some red food coloring you can have bloodshot eye looking eggs.
grated parasan cheese kinda works,
hard candies of a few kinds work really well. think cheap assorted.
as for the tonic water this worked GREAT! take some flat tonic water and pour into a ziplock sandwich bag, probably a cup or a little more, let out most of the air and seal. get a few of these and place around the base of a large bowl or something and kinda crinkle them up looks cool as hell in the blacklight.
sorry its late but we didnt discover this til our party.