The best way to ensure that your cameras and lenses are working optimally is to make sure that you clear dust and debris from them on a regular basis. The dirtier a camera is, the more chance that dust or dirt is going to wind up on your sensor and you may not know it until you're looking at the footage in post. We've shared some tips from Canon about keeping your gear clean, but here's the opposite end of the spectrum: what not to do.
While I'm sure someone, somewhere has done this before seriously, if your camera is not in a waterproof housing, it should never be submerged in water. This also goes for any cameras that are marketed as weather-sealed. A camera or lens being weather-sealed does not mean it can be submerged in water -- simply that it can survive occasional splashes or some rain. Thanks to Anthony for sharing this on Facebook, here is the worst thing you could ever do to clean your cameras and lenses:
This video is meant to be a joke by its creator, because even if that camera partially worked before, it almost certainly will not work correctly now (though cleaning it with salt water might have been funnier since it corrodes electronics). It's important to reiterate again though, this is about the most harmful thing you can do to clean your sensitive electronic gear. Some will find this video either hilarious or irresponsible -- I think it's rather funny, but at times difficult to watch since some of those parts are salvageable no matter what even if neither of these are working. At least it serves as a good teaching tool here where we can definitively say this is a bad idea.