The rubber seal is usually in the lid, just remove it and spray it down with the cleanser and use a q-tip to get down in the small crease of the lid where the seal was. I leave the cleanser on for about 5 minutes and then rinse.
Even though Tea Tree Oil is an all natural essential oil it is dangerous if swallowed like with all other disinfectants. So make sure to keep it in a safe place with your other household cleansers. To learn more about Tea Tree Oil and its uses click HERE.