Going to play the bad guy here, I am with SMD find this sort of thing wrong. That people are doing it not because they want to donate to charity, but more interested in just sticking a video on Facebook showing them getting doused in water. I wonder how many people would do it if they got doused in water but didn't post it on Facebook? None? Maybe, at a guess. Pick a charity that means something to you, donate regularly not just a one off, get no social media kudos...fair play if you want to, but shame that it takes social media peer pressure to do it.
...flame suit on