I was having trouble with the buttons on my Pebble not responding. Emailed support and got this reply:

Thanks for your report. We've found that this issue is often caused by a substance around the button. To try and loosen or remove possible debris, please submerge the Pebble watch under warm water for a few moments. Then remove the watch from the water and firmly press and hold each button (individually) for 7 seconds.

I had to read the instructions several times before plucking up the courage to actually dunk the watch in a glass of water. It seems to have done the trick, but every instinct screamed at me that it was wrong!