It's essentially the 'human blockhead' carnie trick. If you do it right it's strange and perhaps unpleasant, but not painful. The recommended method of learnin

It's essentially the 'human blockhead' carnie trick. If you do it right it's strange and perhaps unpleasant, but not painful. The recommended method of learning how to do it is to use cotton swabs. If you do it wrong, or maybe just have a particularly tight nasal passage, it could definitely be painful. For me, my right nostril is easier than the left. https://en.m.wikipedia.org/wiki/Human_Blockhead https://en.m.wikipedia.org/wiki/Human_Blockhead (Note that performers often pretend to be in pain for dramatic effect. But if they're doing it right, the agony is an act.)