Sprinkle cracker crumbs evenly in 10 crab shells or ramekins. Place 2 or 3 oysters over cracker crumbs in each shell. Melt butter in a small saucepan over low heat; add remaining ingredients, and cook until thoroughly heated. Remove and discard lemon.
Drizzle 2 teaspoons butter mixture evenly over oysters in shells. Place shells on a broiling pan, and broil 5 inches from heating element 5 minutes. Serve immediately.