Probably depends on what city you're in. When I lived in austin, there were a lot of legit ads, and most were very weird. I saw one where a guy wanted other guys to pay $10 each to watch his slave blow a dog. And possibly he'd let you do his salve in the butt. I emailed to see if they were for real, and well, I don't know if it actually happened, but I did get a response saying he was doing this to punish the slave because he'd been bad.
But I had much more luck in the WFM section and posting in M4W. Most of those were looking for casual encounters anyway. If you want a hooker, goto the services section. Also, craigslist is a shithole now. I put up a post once looking for someone with a particular type of gun I wanted to test fire, offering to pay for the day at the range and let them shoot anything of mine they wanted. It got taken down within minutes and I got a rash of shit about trying to sell a firearm. So fuck craigslist. Backpage is where it's at.