A Snot Rock is a rock of mucus located in either the mouth or the throat. It is usually formed overnight when sitting mucus begins to harden. It is very disgusting and I myself have only witnessed it one time.
So I woke up this morning and as I'm about to get in the shower, I feel the need to cough. After I cough I feel a lump in my mouth and so I spit it out and a Snot Rock comes flying out.
To preform: hold one nostral closed and blow out of your other nostral hard enough to make the wad of mucus shoot out of your nose .
like the time Jamielee Cedar-Kelly shot a huge snotrocket in the middle of the mall parking lot. She got a little on her shoe, but she just brushed it off and wiped it on the guy standing next to her.