Sea shells are interesting and unique artefacts that can be harvested from the ocean. Their primary purpose is as a unique decoration, as no two sea shells are identical. However, most sea shells are still alive when harvested. The animal inside must be killed and cleaned from the shell, as well as the barnacles and the outer covering.
Fill a large saucepan with water and bring to a boil over high heat. Place the sea shell into the water and allow it to boil for 10 to 15 minutes. This will remove the animal from the shell.
Remove the shell from the boiling water using a pair of tongs, and set it on a clean towel to dry. Wait until the sea shell has cooled, and use a water hose to shoot a jet of water into the shell, removing any remains.
Fill a large bucket with a solution of 1 part bleach and 1 part water. Soak the sea shells in the bleach/water mixture for 10 to 15 minutes, or until the periostracum is gone. The periostracum is the leathery, flaky outer layer that covers most sea shells.
Remove the sea shells from the bleach solution using tongs and rinse under clean water for several minutes. Use an old toothbrush to scrub away any barnacles that remain on the shell.
Dip the end of a clean cloth in mineral oil and apply a thorough coat over the outside of the sea shell. This will give the shell a shiny lustre. Wipe it clean with a separate, clean cloth.
You can also microwave the sea shells to kill the animal inside. Set the shell in the microwave and cook on high for two to three minutes, then gently pull the remains from inside the shell.
Never use varnish on a sea shell, as it will ruin the natural lustre of the shell.