I got certified and it did hurt.
Well the next time I got sprayed I was at my house. What happend was my wife's pepper spray had accidently gone off in her purse while she was at work. (Punch cone pattern) she said everyone around her was coughing and hacking, so she did what was right and quietly exited along with them.....
Well I was washing off the leather carrier it was in and rinsing off the container.....I started pushing the container back into the leather holder and the saftey twisted around and stuck open so I got a good blast of punch in my face. I was in the bathroom, so I declothed and hopped into the shower. Nice and warm.
ETA: Not OC, but I was at our college's PD late one slow hoot shift visiting one of their officers. We were digging through their old "junk closet" when I found an old can of MACE. I told their officer I was going to shake it up and spray it to see what MACE 'smells' like. I was sitting on a chair and shook it about 5 times when I hit the top of the can on my knee and it shot MACE everywhere, dumped the whole can. Well it does burn and is hard to breath, we both started snotting and had to go outside to get some air. Not as bad as OC, but still rough, you snot a lot more...