Combine brine mixture a large plastic lined stock pot. Large baking bags work really well as liners. Submerge crown roast into mixture, cover pot and place into refrigerator for 6-10 hours.
Remove from brine and wash roast off with cold water. Do not submerge in water, simple wash off the surface. Blot dry with paper towels.
Preheat grill for medium-high heat.
Combine rub ingredients and apply all over the meat portion of roast. Do not use any additional salt as the brine provides this component. Wrap bones with aluminum foil. Tie roast with kitchen twine.
Place roast onto grill and cook for about 2- 2 1/2 hours depending on size. Begin basting roast after the first hour of cook time. Do this every 15 minutes until roast has reached an internal temperature of 155-165 degrees F. (depending on preference).
During the first hour of cook time, prepare the sauce. In a medium saucepan, simmer sauce ingredients over medium-high heat for 2-3 minutes, stirring often. Reduce heat to low and let simmer for 5-8 more minutes. Sauce should be fairly thick. Remove from heat and keep warm. If needed, heat sauce in microwave for a minute right before serving.
Remove roast from grill and place onto a cutting board. Loosely tent with aluminum foil. Let meat rest for 10 minutes. Cut away twine and remove foil from bones. Cut between bones to create individual chops. Serve with warmed fig sauce on top or on the side.