Bring boil-in-bag shrimp-and-crab boil, next 3 ingredients, and 3 1/2 qt. water to a boil in a large stockpot over high heat.
Add potatoes and corn. Cover and boil over medium-high heat 20 minutes or until potatoes and corn are tender.
Stir in shrimp; remove from heat. Cover and let stand 10 minutes. (Shrimp will turn pink, and shells will loosen slightly.) Stir in ice cubes and salt, and let stand 5 minutes.
Drain, discarding boil bag.
Serve with Timmy's Shrimp Sauce.
*6 (4-inch) ears frozen corn may be substituted. (Do not halve.)
Note: For testing purposes only, we used Zatarain's New Orleans Shrimp & Crab Boil and Zatarain's Concentrated Shrimp & Crab Boil seasoning.