3 slices hickory-smoked or applewood-smoked bacon, cut crosswise into 1/2-inch-wide strips
1 cup (2 sticks) unsalted butter, cut into 1/2-inch cubes
4 garlic cloves, peeled
1 1/2 tablespoons chopped fresh Italian parsley
1 1/2ttablespoons chopped fresh cilantro
1/2 teaspoon cayenne pepper
1/2 teaspoon freshly ground black pepper
1/2 teaspoon coarse kosher salt
2 1/2ttablespoons dry white wine
2 tablespoons fresh lemon juice
24 freshly shucked oysters (such as Malpeque or Bluepoint), on the half shell
Cook bacon in heavy medium skillet over medium heat until crisp. Using slotted spoon, transfer bacon to processor. Add butter, garlic, Italian parsley, cilantro, cayenne pepper, black pepper, and 1/2 teaspoon coarse salt. Blend until smooth, occasionally scraping down sides of bowl. With machine running, gradually add white wine, then fresh lemon juice and continue to process until blended.
Place large sheet of waxed paper on work surface. Drop butter by heaping tablespoonfuls onto paper in long log. Using paper as aid, shape butter into 2-inch-diameter log. Wrap to enclose; chill butter until firm, at least 2 hours. DO AHEAD Can be made 2 days ahead. Keep chilled.
Prepare barbecue (medium-high heat). Spread 1/2-inch-thick layer of rock salt on large rimmed baking sheet. Place baking sheet on grill rack and heat 20 minutes.
Cut twenty-four 1/8- to 1/4-inch-thick rounds from cayenne-butter log. Transfer hot baking sheet from grill to heatproof surface. Nestle oysters in hot rock salt. Top each oyster with slice of cayenne butter.
Return baking sheet with oysters to grill. Close grill and cook until butter melts and starts to brown, 6 to 8 minutes. Spoon shallow layer of additional rock salt onto each of 6 plates. Nestle 4 grilled oysters in salt on each plate and serve.