Personally, I don't discharge the smoke to go back through the stem. I just don't seal my lips, and the smoke just dissipates through my mouth, but the key is to not see your own smoke, or you are doing it too fast. You never see smoke coming from men clenching in old movies, but you do cigarettes or cigars.
I never saw pipe smokers making smoke growing up, working men, farmers, men walking to church with pipe clenched in the jaw. It was always the newbie that you saw making billowing puffs of smoke, like kids with a toy. So, I just naturally have always tried to keep the smoke as invisible as possible. My daughters would tell you that the only time they see smoke coming from me is when they've pushed me too far, ha ha.