I have done it and its not hard. Just lick the handle (blunt and rounded) of a spoon and slide it carefully into your nostril. Point it straight back into your nasal cavity (not pointed up or down) until you hit bone ( it goes back pretty far). I would do it sittingdown to avoid any “running with scissors” accidents. To answer your question, I would say it is a no horseplay activity.
I perform the Human Blockhead and it is dangerous. When you use a sharp object or an object with a point you could be injured. When doing the stunt you could be bruised badly or start to bleed in your nasal cavity which will send you to the hospital.If you do get cut call the emergency quick and you will be sneezing, coughing, spitting, and swallowing blood. So, is the human blockhead dangerous? Yes, very dangerous if used with the “normal” tools.