Firstly I cant tell what a relief it is to know others have struggled with this too- If my 'bubbles' doesn't move in a 2-3 hr period I begin to get stressed and anxious and can;t do anything until I feel movement.
Definatly cold water and lying down on my side works, but of late (past week or so) sometimes this doesn't even work. My theory is that bubbles legs and arms are facing my back now and seen I'm due now theres not much room for much movement, so now I feel for the hiccups (which happens daily)..Going for a brisk walk also works well.
HTH