Now, whether you think it can or can't doesn't really matter for the sake of my writing research :) That's the cool thing about fiction. I get to decide if it works or doesn't. So, while my character is waiting for her ebay order to arrive, I've got some thinking to do :)
One of the more interesting items I found on there was a woman who claims she found a bunch of lost spells that her great-grandmother--a witch--left to her in an old trunk. She's using these spells to creat "mojo" type bags and other sorts of pendents. Very interesting! So interesting, in fact, I had to dig a little deeper and I found her (and her husband) on the 'net:
Lady Isabel's Lost Spells at lostspells.com
But, if you'd like, you can shop around at eBay for other forms of protection:
Protect yourself from Evil
Okay, I'm back to writing now ;) Let me know if you order something and how it works out for you!