Slow Cooker Meatballs

1 (32 oz.) jar grape jelly
2 (12 ounce) bottles tomato-based chili sauce (such as Heinz®)
1 pinch cayenne pepper (optional)
3 (5 pound) bags frozen cocktail-size meatballs 
Use a liner in your slow cooker for easier cleanup 
Combine grape jelly, chili sauce, and cayenne pepper in a saucepan over medium-high heat; cook until warm, 5 to 10 minutes. 

Place meatballs in a slow cooker and top with grape jelly mixture.

Cook on Low for 3 to 4 hours.