Yes. I blew something out of my nose that was shaped like a small capsule that was covered with gray/green mucous-like matter. I guess the mucous enveloped it to protect my body from it. I believe it was the head of something that I blew out a week later that looked like the body of a baby dragonfly. It was also encapsulated in a mucous - clear mucous, therefore, it was easy to see that it was an insect's body with a long tail and no head--actually shaped like a tadpole, but because it had budding wings and something that resembled a dragonfly's head that I had hawked out a week earlier, I believe that it was a baby dragonfly that I breathed in, or a larvae, but I cannot even begin to remember or imagine how it entered my nasal cavity.
Yes there are parasites that can inhibit Human Nasal passage. There can be many kinds of such parasites that can infect a human nasal passage. One of them is a kind of Pentastomiasis. The larvae enter the human nasopharyngial passage and cause pain and itching in the ears, throat, head, vomitting etc. They can be as long as 5-10mm. They can cause intense damage to facial nerves so your husband better get himself checked for any such parasites. For reference see the link below: