It does work, but trust me it's really not a pleasant experience, I felt horrific at times with dire stomach cramps etc. I've suffered from eating disorders for quite a long time, and originally I did swear that I would never use them. But when I progressed from anorexia to bulimia I did use them and it just got out of control.
It may well not help so much anyway, as if you think I'm gonna flush it out so it doesn't matter and I can eat more, then it's like having low fat spread and eating twice as much. You will still absorb the fat and calories to some degree.
Seriously, DON'T go down that route.