This might just end up doing the same thing with extra steps but for me the most effective has been holding breath until it starts to become slightly uncomfortable and then start drinking a full glass of water while allowing myself to take short breaths of air as necessary between swallows. Something about the swallowing motion combined with short breaths seems to "reset" the diaphragm like a champ for me. Breathe slow and relaxed for the minute after to ensure it's really gone :)
1. Inhale until lungs are at full capacity.
2. Hold your breath as long as you manage comfortably.
3. Breathe in and out slowly for a couple of breaths. I.e. don't gasp for air.
I also long suspected it may work by reducing the activity/stimulation of the diaphragm.