Add the mayonnaise, sour cream, and chili sauce to a food processor or blender.
Measure and add the lemon juice, minced dill pickle, minced green pepper, and minced green onion.
Add the grated or bottled horseradish, Worcestershire sauce, Tabasco, sugar, salt, pepper, paprika, and minced parsley.
Blend briefly until the mixture is thoroughly combined but not overprocessed; scrape down the sides if needed.
Transfer the dressing to a covered jar and refrigerate until serving; stir before using.