Dip oysters in egg, and dredge in cracker crumbs. Place on a pan, and chill 2 hours, if desired.
Stir together ketchup, horseradish, and, if desired, hot sauce; chill.
Pour oil to a depth of 1 inch in a Dutch oven; heat to 350°.
Fry oysters, in batches, 3 to 4 minutes or until golden brown. Drain on paper towels. Serve immediately with sauce.