Preparation Place eggs in large saucepan. Add enough cold water to cover by 1 inch. Cover pan; bring to boil. Remove pan from heat and let stand covered for 10 minutes. Drain. Let eggs stand in cold water until cold, about 30 minutes. Peel eggs; halve lengthwise. Transfer yolks to processor. Trim small slice off bottom of egg white halves; place on tray, cavity side up. Process yolks until smooth. Add mayonnaise, 3 tablespoons horseradish, pickle juice, pepper, and salt to yolks; process until smooth. Adjust seasonings, adding more horseradish if desired. DO AHEAD Can be made 1 day ahead. Cover whites and filling separately and chill. Transfer filling to pastry bag fitted with 1/4-inch plain tip. Pipe filling into cavities of egg whites. Garnish with parsley.
Preparation Place eggs in large saucepan. Add enough cold water to cover by 1 inch. Cover pan; bring to boil. Remove pan from heat and let stand covered for 10 minutes. Drain. Let eggs stand in cold water until cold, about 30 minutes. Peel eggs; halve lengthwise. Transfer yolks to processor. Trim small slice off bottom of egg white halves; place on tray, cavity side up. Process yolks until smooth. Add mayonnaise, 3 tablespoons horseradish, pickle juice, pepper, and salt to yolks; process until smooth. Adjust seasonings, adding more horseradish if desired. DO AHEAD Can be made 1 day ahead. Cover whites and filling separately and chill. Transfer filling to pastry bag fitted with 1/4-inch plain tip. Pipe filling into cavities of egg whites. Garnish with parsley.