Grate onion half on large holes of a box grater to yield about ¼ cup. Place grated onion in a double layer of paper towels; squeeze to remove excess liquid.
Stir together grated onion, mayonnaise, peppers, vinegar, and hot sauce in a large bowl until well combined. Fold in cheeses. Cover dip, and refrigerate for at least 30 minutes. Serve with crackers, crostini, and/or crudités.
