1. Mix chili sauce, vinegar, horseradish, garlic and salt in a bowl. Reserve 1/2 of the marinade. Add chicken to bowl; turn to coat. Cover; marinate in refrigerator for about 5 minutes.
2. Preheat grill or broiler. Remove chicken from marinade; discard marinade in bowl. Place chicken on grill or on broiler pan.
3. Grill or broil chicken, turning and basting frequently with half the reserved marinade, until juices run clear when meat is pierced with a knife, about 30 minutes.
4. Heat remaining reserved marinade in a small saucepan, stirring occasionally. Serve hot alongside chicken.