A modified multi-chambered container including a container body defining a central (e.g., liquid) chamber, a neck defining an opening to the central chamber, a flange extending upward from the neck, and a groove formed in the neck around the first opening. A collared O-ring includes an annular base mounted in the groove, and a ring-shaped collar extending from an upper portion of the base toward the opening. A hollow ball member is mounted on the neck such that an outer wall of the ball member contacts the O-ring collar. A housing is attached to the container body that pushes the ball member against the collared O-ring.