This is my dirty trick, and it ain't too scientific, perfect, or probably even right. But if all else fails, to include waiting to see if your gushers calm down after a lengthy chilling in the fridge, I've been known (when I bottled) to do the following:
Get a flat bottle opener, one that will allow you to pry ever so slightly on the already affixed cap.
Pry ever so slightly on the already affixed cap-> as in barely, and I mean slowly and barely lift one edge of the cap so that you can faintly hear co2 escaping. You should need to do this in a quiet room because the amount of co2 escaping will be so minimal.
That said, how long you keep the edge of the cap slightly lifted is up to you. I found good results by lifting for an initial burst of co2, then let the cap back down, and if you haven't lifted or bent the cap to much, it will reseal itself.
Experiment with when you try this - after chilling or before, and experiment with how many you do at a time. I had good luck releasing co2 prior to chilling (a 6'er at a time) and then chilling them down to serving temp. Ymmv