In the kitchen, a string of onions, garlic or hot peppers hanging up may just seem like a functional or decorative way of storing them. But the magical protective function of onions, garlic and peppers is the primary reason for hanging them in that way.
Their smell and their many protective layers of skin are both off-putting. They are said to ward off everything from snakes, ill-wishers and Vampires.
Strings of snail-shells, too, have a magical function, being considered a charm for promoting fertility, prosperity and well being. The spiral is the basic universal pattern of growth, and a string of spirals repeats the motif both of the spiral and the knotted-cord. In the garden too, lines of snail shells are a traditional charm for growth.
This practice is enshined in the nursery rhyme, Mary, Mary, Quite Contrary, which tells of "Cockleshells all in a row."
Brightest of Blessings