Take the other half of your spice rub and apply it to the chicken. Don't worry too much about getting it on the skin. Skin won't let flavor reach the meat, so try to work your spice rub in under the skin as much as possible. Get it inside the chicken as well. Just because you put rub in the beer doesn't mean that it will season the inside too much. The spice in the can adds flavor but not like direct contact.