Recently one key on my one year old Ducky One (Cherry MX Blue)
https://geekhack.org/index.php?topic=91150.0 has started to double click and not register and after fixing it I thought it might be useful to report my easy solution here in case somebody else runs into the same problem. I have had this happen to me in the past and strangely enough none of the instances were due to liquid spill.
1. remove keycap
2. push the switch piston with a small object (paper clip, retracted pen)
3. drop in a few droplets of alcohol (preferably 91%) with a Q-tip right into the switch
4. press the switch a few times
5. replace the keycap
The alcohol is perfectly safe for the keyboard, so in order to make sure that it actually reaches the metal contacts I usually seep in a generous amount of droplets. I haven't had a liquid spill yet, but this method can work for that as well, just using more alcohol to rinse the liquid where it spilled. Alcohol evaporates extremely fast, so it'll help to dry out water when it mixes with it, and it'll also help clean any other liquids by dissolve them.
