Hmmm - Dried dung beetles would be one of my more original ideas.
They are everywhere on our land (which is a nice direct link) and do love to come inside and die on the windowsills. They are single minded, and industrious creatures so I feel their 'mojo' would not be easily worn out or distracted.
I'm going to use them to make protections that 'drag down and compost' negative energy (my own or others sent my way) much like the little chappies do with shit.
This feels more comfortable to me than a standard 'witch bottle' that feels to me more like an 'accumulator' than a shield, though I realize my view of this is not the most common one.