Have you ever laughed or coughed and blew Pepsi out your nose? There's a flap at the back of your throat opening that's suppose to prevent that from happening. If that flap gets turned or dry, it causes what they call reverse sneezing and the hound will snort and sneeze to try an get it right again. Usually a palm full of water in the hounds mouth will clear it up. I've also used what they call a "puffer bottle". Fill it with water and squirt it down each of the hounds nostrils, this will flush out the nasal cavity and moisten the flap at the back of the throat.
Note; the hound won't like you for a while after doing this, but he'll get over it soon...lol