Do not make it a habit to collect "live" shells, but occasionally you or your children will pick up one which has stranded on the beach. There are several known methods for cleaning your live shell specimens.
Burying: This is probably the easiest, but takes a couple of months. Locate an area in your yard where you can dig a hole. Bury the seashells about 50 cm (deep enough so animals will not dig them up). They need to remain buried until insects, larvae, worms, and bacteria remove all the tissue. The longer you leave them the better.
Freezing: Place seashells in a water-tight plastic bag, cover with water, then place in the freezer (just like you would do to fresh fish). When you are ready to clean them, let the bag thaw at room temperature until completely defrosted. You should be able to grab hold of the animal inside and gently pull it out.
Boiling: Place seashells in a pan, add water, and bring to a boil. Let boil for a few minutes (the more shells the longer). Use tongs to remove one shell at a time. So you don't burn yourself, grasp shell with gloves or a towel and gently pull out the animal tissue inside.
Microwave: As long as you don't mind the smell in your microwave, this is an easy method. The time it takes to cook your seashells can really vary by microwave, so just try it until you figure out how long for each shell. Grasp cooked shell with gloves or a towel and gently pull out the animal tissue inside.
A seashell that is found already dead is actually a lot easier to clean. Follow these easy instructions:
Bleaching: Soak the seashells in a 50-50 solution of bleach and water. The length of time depends on the type of seashells and the quantity of seashells being cleaned. Just be sure to remove them when the "periostracum" is gone.
The periostracum is a thin organic coating or "skin" which is the outermost layer of the shell of many shelled animals, including mollusks and brachiopods.
periostracum
Barnacles: If there are still barnacles and other matter on the seashells, you can use an instrument, such as a dental pick, to chip off the material. Other useful tools are a toothbrush, grill brush, wire brush or a water pick.
Shining: If you want to give your seashells a nice finish, you can wipe them with a mineral or baby oil.
Cleaning Sand Dollars
If the sand dollars are dead let them dry for a few days, then put them in a container with a little bleach. You may need to brush them gently. Do not let them bleach for too long as they tend to crumble.If you have the time you can just let them set all winter and they will dry and whiten by themselves.
If you leave sand dollars out in the sun too long they tend to become brittle and break easily. There is a commercial preservative that can be brushed on to harden the sand dollar.
