Yes, I did try it and worked very well for me. I lost 25lbs and it has stayed off, even though I have not been on the diet for about two years now.
The one I tried is called the heart-bypass diet/Grapefruit diet. No I didn't have heart problems, I just wanted to lose weight.
Really simple:
Breakfast; one egg cooked any way you want, two strips of bacon and a half a grapefruit or 6oz. glass of grapefruit juice.
All other meals, all the meat you want, cooked anyway you want, with a glass of grapefruit juice.
Most important rule: Do not eat anything white, bread, rice, potatoes, any fruit, etc.
Every ten days you can eat anything you like for two days.
I liked it and it worked for me.
Oh yeah, you can still drink beer!