What it is
Margins are a time and a place, not a separate universe of tackle. Late in the day on a commercial, carp and F1s move into the edge to feed. Paste, meat, corn, worm and pellet all catch. A short pole or a waggler down the side puts a bait on the shelf.
The mistake is fishing the edge all day, feeding it into a cloudy mess, and then wondering why the fish don't come. Keep it quiet, feed it late, and use an elastic or a hooklength that can stop a fish that has two yards to a snag.