A grommet for sealing the propellant charging opening in a pressurized dispensing container has a crown portion inside the container, a base portion outside of the container and a resilient neck joining the base and crown. The neck dimensions are such so as to provide three interference fit sealing zones between grommet and container base. The neck has a length less than the lip of the container opening to provide a first interference fit sealing relationship. The neck diameter is greater than the diameter of the lip to provide a second interference fit sealing relationship. The corner between neck and crown is rounded to provide a third interference fit sealing relationship. The grommet has a central opening so that a stretch pin can be inserted to stretch the neck during the injection of propellant. The extended neck lifts the crown from the container and causes the neck to contract to provide a passageway around the neck and under the crown for injected propellant.