I honestly would do that.  Last Wednesday was a perfect time for me to do it - it was a catfish lunch date - but I was still hungry, so I just said whatever I felt like saying, ate, and left.  It was cheap, and I had a "person" who was on their best behavior (trying to pull me in with their fake "nice" personality) talking to me.  They certainly weren't going to insult me.  That's why I didn't just get up and leave.  But like I said, I totally would if I felt like it.