I got some out of curiosity.... its a pleasant tea to drink...I drink it instead of coffee sometimes (which saves me about 50 cals of milk/creamer). Weight loss? No. Soothing warm drink... Yes. Any good Ooolong version will do you just as well.
I haven't tried it, but I've read about it. But think of this: If you eat right and exercise every day, you don't need the tea to lose weight.
Another thing to keep in mind - sometimes you might be lucky enough to find something that might really help, but as soon as you stop taking it, you gain back the weight. If you calculate the number of calories you need each day, work up an exercise routine and make actual life style changes, you will be able to maintain your weight loss.
You might also check over in Weight Loss Alternatives - someone there might have tried it. If you decide to try it, let us know how you turn out. Good luck.