In a small bowl, combine yogurt and chili sauce.
Stir in egg white, green or red sweet pepper, onion, pickle, pimiento, and Worcestershire sauce or horseradish. Cover and chill in the refrigerator for at least 2 hours.
To serve, stir in enough milk to make the dressing the consistency you like. Makes 1 cup (sixteen 1-tablespoon servings).
You can store the prepared salad dressing in the refrigerator for up to 1 week.