What it is
Luncheon meat is a strong, cheap hookbait. Cubed, punched, or on a hair, it catches carp in the edge and barbel in a crease. It also sours in the sun and it is banned on many commercials in the warm months because it kills swims and makes a mess.
If it's allowed, cut it cold, cube it, and don't leave a pink slick in the margins. If it's banned, that's the end of the conversation.