Add the Chex cereals, mixed nuts, pretzels, and the mix-ins of your choice to a 6-quart slow cooker insert. Stir gently to combine. (Note: if your mixins are chocolate and can melt, hold off on adding those in until the very end).

In a separate microwave-safe bowl, add the stick of butter. Heat in 30-second intervals until completely melted. Alternatively, you can melt it over low-medium heat in a saucepan.

Add the Worcestershire sauce, seasoned salt, garlic powder, and onion powder to the melted butter and stir well to combine.

Pour half of the melted butter mixture over the cereal and mixins, and toss well to coat. Add the remaining half of the butter mixture, and toss well until everything is evenly coated.

Place the lid on the slow cooker and cook on “low” for 3 hours, stirring every hour to encourage even browning.

Once the cooking time is up, turn off the slow cooker and allow it to cool with the lid off until room temperature. Stir the mix several times to help heat escape.