After purchase, you can keep them in saltwater and in the refrigerator for 1 to 2 days. After that, you have to keep them in the freezer.
Clean and cut them into small pieces and add some salt. Put them in the freezer and thaw them for about an hour before cooking.
1. Cut off the mouth with a knife (bumpy area is the mouth).
2. Make cuts with a knife or a scissors and separate the meat from the skin.
3. Wash them with saltwater and cut them into small pieces (washing them with freshwater may take away some of the sweetness from the sea squirts).