Place ham in a large Dutch oven or stockpot. Cover with water to 2 inches above ham; cover and refrigerate for 24 hours. Drain; rinse well with warm water. Drain.
Preheat oven to 325°.
Trim fat and rind from ham. Score outside of ham in a diamond pattern; stud with cloves. Place ham, skin side down, on the rack of a broiler pan coated with cooking spray. Place rack in pan; pour 1 cup apple juice over ham. Cover ham loosely with foil. Bake at 325° for 2 1/2 hours, basting occasionally with remaining 1 cup apple juice.
Remove ham from oven (do not turn oven off); uncover ham. Combine sugar and mustard; brush over ham. Bake, uncovered, at 325° for 30 minutes or until a thermometer inserted into thickest portion registers 140°. Place ham on a cutting board; cover and let stand 10 minutes before slicing.
Soaking the ham in water draws out some of the sodium so the ham won't taste too salty.