A facial tissue or square of bathroom tissue screwed into a tapered spiral (resembling the blending stick used by pastel artists), which is used instead of a finger to excavate a nostril (for reasons of hygiene or disposability).
She: "Eew! I can't believe that you're using a snot snail in front of me!"
He: "OH? Would you prefer it if I used my finger to get out the booger
? Or if I used yours?"