I don’t know about you, but I wish I came accross this a long time ago. If this helps you out then I’m glad.
Step 1: Breathe in as much air as you can.
Step 2: Swallow, then take another breath, without releasing the air already in your lungs (this should only be a small breath, considering how full your lungs are already).
Step 3: Repeat the breathe/swallow cycle at least 2 more times until you can’t swallow anymore.
Step 4: Exhale, and enjoy your hiccup free breathing.