Rinse the seashells under running water to remove loose sand and debris
Soak the shells in warm water mixed with a small amount of mild dish soap
Gently scrub the shells with a soft toothbrush or cloth
Rinse thoroughly with clean water
Soak the shells in a solution of equal parts water and white vinegar if needed to remove buildup
Do not soak too long if the shells are delicate or polished
Rinse again after vinegar soaking
Let the shells air dry completely on a towel
Wipe off any remaining residue with a soft cloth
Apply a small amount of mineral oil or baby oil if you want to restore shine