Rinse shells under fresh water to remove sand and loose debris
Soak shells in warm water mixed with mild dish soap for 15 to 30 minutes
Scrub gently with a soft toothbrush or cloth
Use a toothpick or soft brush to remove dirt from crevices
Soak shells in a solution of 1 part bleach to 10 parts water for a few minutes if needed
Rinse thoroughly with clean water after bleaching
Soak in hydrogen peroxide instead of bleach if you prefer a gentler option
Let shells air dry completely
Rub a small amount of mineral oil or baby oil on dry shells for shine if desired
Wear gloves when handling sharp or fragile shells