I LOVE it. Back in the day (even older than some of us), they used to load muzzle-loader pistols with a lite load of powder (just a few grains) and on top was a wax ball with barbs. The barbs were to stick to the target's clothing to mark the hit. There were also fencing swords with a similar wax ball held on the tip with thread. The thread would break on a hit leaving the ball in place.
Id be up for bringing back public duels