We can assure you that the failure rate without a customer using the rubber grommet is very low. We have collected information since we recently started including them and we found that when it's being used it's effective and when it's not there the failure rate is still pretty low.
In the past, we have had customers requesting these for their charging port, but we have had many customers before the rubber grommets that have not had issues when using their machine without it. We have also found that some customers didn't know our shavers are not waterproof, they are water-resistant, therefore they were submerging them in water.
However, we would be more than happy to send you a complimentary rubber grommet if you reach out to our customer service team and confirm your shipping address. Please let us know if you have any other questions or concerns. We appreciate your business!