Gently mix corn, rice, and wheat squares, oat rings, mixed nuts, mini pretzels, fish-shaped crackers and sesame snacks in a large roasting pan (e.g., 13x24-inch aluminum roasting pan), taking care not to break cereal.
Stir bacon drippings, unsalted butter, Worcestershire sauce, MSG, liquid smoke, cayenne pepper, seasoned salt, chili powder, garlic powder, and hot pepper sauce together in a microwave-safe bowl. Cook on high in microwave oven for 3 or 4 30-second intervals, stirring each time, until mixture is warm, liquid, and fully combined.
Stir seasoning sauce continuously as you pour half over the cereal mixture. Gently stir the snack mix and seasoning sauce with a slotted spoon until thoroughly coated; do not crush cereal.
Bake in the preheated oven until sauce is completely absorbed and the snack mix is crisp, about 2 hours; stir gently every 15 minutes. Cool completely and store in airtight containers. May be prepared in advance and stored in the freezer using airtight freezer bags.