Article: the nostril.  At this step in the process be particularly vigilant for any trailing mucous which might be attached to the payload. These un-noticed "stringers" can jeopardize the entire operation. This should launch the material sufficiently far away from you that it becomes someone else's problem. ..never wipe it on your shirt or trousers - it's always a dead giveaway. If the offending article sticks to the ceiling, it'll be there forever.

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Position the index finger of the opposite-side hand alongside the exterior of the obstructed channel.  slip the thumb as deep as necessary into the nostril. Using the thumbnail, delicately clamp onto the dried mucous mass. Slowly withdraw the thumb and its payload from the nostril. Return the hand to a more natural position and discreetly execute a flicking motion with the thumb. Remember. Beware of flicking too hard.