1. Combine first 7 ingredients. Sprinkle skin and cavities of chickens with salt mixture. Place chickens in oven bag; twist end of bag, and close with tie. Chill 24 hours.
2. Light 1 side of grill, heating to 350° to 400° (medium-high) heat; leave other side unlit. Reserve 1/2 cup beer from each can for another use. Place each chicken upright onto a beer can, fitting into cavity. Pull legs forward to form a tripod, allowing chickens to stand upright.
3. Place chickens upright on unlit side of grill. Grill, covered with grill lid, 1 hour and 30 minutes to 1 hour and 40 minutes or until golden and a meat thermometer inserted in thickest portion registers 170°. Let stand 10 minutes. Carefully remove chickens from cans; cut into quarters.