Pour rock salt into an ovenproof skillet. Shuck oysters, leaving meat in bottom shell. Place shells on the salt. Spoon 1 tablespoon BBQ Relish on top of each oyster. Broil oysters, 6 inches from heat, for 3 to 4 minutes or until relish begins to caramelize. For aroma and appearance, stir pickling spice into the rock salt, and serve oysters atop the mixture in the skillet or on a serving tray. Garnish with cilantro.