In a large skillet, bring 1/4 inch of water to a boil. Add the clams, cover and cook until opened, about 3 minutes. Transfer the clams to a baking sheet to cool. Strain the cooking liquid through a fine sieve into a medium bowl. When the clams are cool enough to handle, remove them from their shells and pull off the brown outer membrane. Rinse each clam in the cooking liquid, then strain the cooking liquid again through a fine sieve to remove any sand or grit.