So you've spent a day out on the beach hunting seashells and now you have a nice stash. As you sit down under a palm tree and look over your finds, you notice that some may smell bad, are covered in grime or algae or are covered in barnacles - not pretty! Your sea shells need a good cleaning!
To begin cleaning your shells, simply let your shells soak in a 50-50 solution of bleach and water. There's no set time that you should let them soak, it just depends on how many shells you have and how dirty they are. This bleach-water solution will clean off any periostracum left on the shells, leaving a beautiful, white shell underneath. Periostracum is simply described as a thin, organic outer layer on the shell. It is usually brownish in color and not very pretty.
If your shells have barnacles left on them and the bleach-water solution doesn't remove them, use an instrument like a dental pick, toothbrush or grill brush to pick or scrub them off.
Finally, to really make your seashells shine, cover them with a fine layer of acrylic paint or wipe them down with mineral or baby oil. This will help protect the shell as well as bring out its natural beauty.