How to revive wilting hydrangeas

I count hydrangeas one of my favorite flowers, after peonies. With all the crazy weather we had in Baltimore, most of my hydrangeas bushes are frail and with very little change of flowering like previous years.
This past weekend we celebrated little M 3rd birthday, and being my first toddler party with parents and kids from his pre-school I decided to buy four bunches of blue and white hydrangeas from Whole Foods, but unfortunately, as in previous times, within a couple of hours all of them were wilting…

I have heard about the cure for wilting: hot water, but never came to try it, until today.
I started with the white ones, and these were the steps I used:
1: boil water enough to cover the stems a couple of inches
2: cut off at least one inch of the stem and put it immediately in the hot water
3: witness the miracle of revival!

Some of the stems were revived quicker than others. Some took as little as a couple of minutes while others took at least 4 hours. I should mention that I bought the flowers on Saturday morning, and only did this revival process this afternoon (Monday).

Some of the pics from my foyer and living room during the party: