Yes, I did this a few times a couple of years back when I was still single.
It was fun and I found it way better than internet dating. Obviously being a bloke I can only tell you about my side of things.
Obviously the first thing to do is go for a venue with a similar age bracket. One I went to didn't really enforce it (I suspect they had to make the numbers up). So you end up with like 40+ talking to a 23 year old which is nice but ultimately a waste of each other's time.
I think you do need to have a certain level of confidence that you can keep a conversation going for 3 minutes. It's not that hard really. If in doubt, revert to the usual topics like job, hobbies etc. By your 10th "date" you'll be sick of the same questions so having a couple of fun ones is a good idea.
Most people are very nice, even if you are obviously not your type. There's only one lady who was so rude that I ended up just saying "Why don't we just not bother and just stay silent for the remainder of the time we have left"
At the end of the day though remember that Rome wasn't built in a day. Just because you don't meet Mr Right on your first try, doesn't mean you shouldn't go back and try again. Let's face it, do you stop going to the pub because you didn't pull one night?
I went about 3-4 times. Got a fair few ticks, of which I managed to get a few dates. Dating one lady for a while who did turn into a bit of a bunny boiler after I dumped her but that's another story.....