Do you know what a "booger check" is? You can do one yourself (something I highly recommend before you go into an interpreting job. Don't ask.) or if you have a best friend - someone you trust with your life - you can ask them to perform the deed.
Other than my husband and sisters, this is the only other person I'd trust. Sue invented the "booger check" and had no qualms asking for help. It was much easier to ask for inspection than to find out later there was an issue - after waiting on several customers.
So, what if you're chatting up a casual friend or someone you just met or the person interviewing you for a job and their nose has an "uninvited guest" in it? Now what? How can you concentrate? Doesn't it make you want to touch your own nose? You begin to wonder if you might be suffering from the same malady. OMG! What to do, what to do?
I can't help you out with this one because I was faced with the same problem just the other day and I didn't say a word. I can only imagine what the poor sucker thought when he/she (notice the vague pronoun?) glanced into the rear view on the way home. I'll bet there was some shrieking/swearing (still avoiding gender identification) at the first red light.
Some years ago I told my friend, Cathy Monroe, that she had a poppy seed stuck between her two front teeth. She was working the counter at the license bureau. It was about 1:30 in the afternoon so it had been there since lunch. She immediately smacked her co-worker for not telling her about that black morsel.
How about the zipper thing. Do you tell a guy you don't know well? What if he's conducting a meeting - standing in front of everyone? On that occasion I did raise my hand. I mean, the poor guy. He took it well, turned his back on us and took care of business.
How about bad breath? No how, no way I'm telling someone their breath stinks. Same thing with body odor.
So, what do you do?