I haven't but two friends have with VERY different results! One ate healthily and found that because she behaved herself and didn't really eat much fat they didn't seem to increase her weight loss by much. The other always has trouble sticking to plan. She had several very unfortunate 'accidents' and altho she did lose a few lbs the side effects were too unpleasant to mention!!
I think for some ppl the sheer threat of what can happen is enough to keep you off the takeaways! But I'm not sure how effective they are if you already follow a low fat plan? That said like most of us I wouldn't mind an extra few ounces a week coming off!