Light the grill and let the coals get hot and white. Slide the coals to the edges to make a ring.
Clean a whole chicken, removing the giblets and neck from the cavity. Rinse chicken inside and out with cool water. Pat dry with paper towel.
Pour out half the beer or soda. If desired, add smashed garlic clove, a slice of onion, or a tablespoon of fresh herbs to the liquid in the can. Place the can inside the rack, then place the chicken over the can. Stuff the neck cavity with a small potato or onion. If using olive oil, rub generously over chicken then apply a seasoned rub. Place a small tin pie plate in center of grill and fill with about 1/4 cup of water. Place chicken in center of pie plate.
Close the grill lid. Cook chicken for 1-2 hours until internal temperature reaches 180°F and the chicken is dark golden brown and crispy. Note: if you use olive oil, the chicken will become dark brown early. Check internal temperature before eating.
Using tongs, carefully remove chicken from the rack and beer can in an upright position. CAUTION: The liquid hot could be boiling!
Carve or quarter chicken as desired.
Make sure you use a grill with a lid large enough to cover a chicken standing.