Turn your slow cooker on and add the cereals, pretzels, crackers, and nuts.
In a small bowl, combine the melted butter, garlic, onion powder, Worcestershire sauce, paprika, seasoning salt, and Sriracha. One small dash of Sriracha will not make the snack mix spicy, it simply adds flavour.
Pour the butter mixture over the ingredients in the slow cooker and toss gently but thoroughly with a rubber spatula (this prevents the ingredients from breaking) until everything is well coated.
Cook on high in your slow cooker for about 2 hours, stirring every half hour or so. I recommend taking the lid off the slow cooker for the last 15 minutes of cooking to let any moisture evaporate.
Be sure to let the snack mix cool completely before packing it up for storage in an airtight container. This will prevent the snack mix from becoming soggy and keep it nice and crispy. The best way to do this is on some parchment paper on a large tray or baking sheet.
Once the snack mix is cooled completely, store it in airtight containers or serve immediately.