There is a woman that I know of that is very similar to the one you are involved with right now; very hot, flirts with tons of guys, dresses provocatively/attention *****, etc. I've known her for about a year and she is "with" a new guy almost every month, literally lol. I don't really know her on a very personal level, so I'm probably only seeing about 10% of what she is actually like haha.
I think you know what to do and to be honest you really don't need to be taking advice from others on here, though it's definitely an interesting story and something others can learn from. As you know from direct experience, these women are not at all stable and to be quite frank probably have legitimate emotional/psychological disorders.
As I had mentioned earlier, the issues comes when men get involved with women and they either are too blind to see these women for what they are or they lack the experience necessary to know how to spot them. If you have been going out with women like these and overlook these issues or aren't aware of them sooner than you think you develop feelings for them and it becomes difficult to let them go. Again, you don't have this issue at all.