Add the Corn Chex, Rice Chex, Wheat Chex, pretzels, nuts, and bagel chips, rye chips, or cheese crackers to a large slow-cooker crock. Stir gently until the dry ingredients are distributed without breaking the cereal.

Melt the unsalted butter, then whisk in the Worcestershire sauce, seasoned salt, garlic powder, and onion powder. Continue whisking until the spices are dispersed through the butter.

Pour the seasoned butter over the cereal mixture. Toss carefully with a large spoon or spatula until the coating reaches as much of the mix as possible.

Cover and cook on LOW for 2 to 3 hours. Stir every 30 to 45 minutes, paying special attention to the bottom and edges of the crock so the butter mixture does not settle or scorch.

For better moisture release, leave the lid slightly ajar if your slow cooker permits. Alternatively, remove the lid for the final 20 to 30 minutes of cooking.

Spread the finished Chex Mix onto parchment paper or rimmed baking sheets. Let it cool completely for 15 to 30 minutes before transferring it to an airtight container.