It is pretty clear that it's banishing demons and evil spirits, so I don't know that I'd call it a talisman. It's not a charm, you know? And it's not general bad luck, like throwing salt over your shoulder if you spill it in the west. It's against *things*. I don't know if I'd call it secular either-- it's eems pretty shinto to me, especially with the purification elemant, though I'd have to check.