Boiling or steaming - before boiling or steaming shellfish, discard ones that have an open shell that won't close. Add to boiling water or steamer. Cook until shells open, about 3-5 minutes.Discard shellfish that shells do not open after cooking.
Barbecuing - place live shellfish on grill, and cook until they open. Discard any shellfish that do not open after cooking.
Why don't you try some fresh shellfish?