There are two types of snails that are commonly used: escargots de Bourgogne (large, meaty snails from the Burgundy region of France) and escargots petits gris (small gray snails). Live snails must be degorged to rid them of impurities and excess juices. To do so, mix them with rock salt and let them rest for at least 3 hours, then rinse them well under cold running water. Bring a large pot of water to a rolling boil, add the snails, and boil for 5 minutes. Drain well but do not refresh. Using a small pick, remove the snails from their shells.