I have always had some trouble with this. If I simply pull the smoke into my mouth and then attempt to blow out my nose, the smoke does not go along for the ride. Ive tried pushing the smoke with my tongue but cant get the smoke to flow through my.............velopharyngeal sphincter.To address not being able to do it or having difficulty doing it:
It's very easy just to hold smoke in your mouth and breathe in and out of your nose without involving the smoke.
As mentioned, for some reason it's very easy to blow cigarette smoke out of your nose but not pipe (or cigar) smoke. Just as inhaling said smoke from a cigarette is nothing like inhaling pipe (or cigar) smoke.
The difficulty is not inhaling, coughing, or burning your sinuses/inside of your nose when getting pipe (or cigar) smoke to come out of your nose. Some people or very used to/practiced at doing it but for others it's akin to the first time you inhale smoke and hack up a lung.
The whole point of this thread is sure, you can force your way through the hacking and burning and eventually get used to it but you don't have to. In fact you don't need the smoke at all to get a small burst of flavor. Not everyone is a seasoned or practiced smoker and this a way for those that aren't to enhance their smoking experience. (You don't have to make faces or noises either.)
A slight chewing mime works for me. I also saw a video where they mentioned initiating swallowing which for some reason works as well.