The weight belts are so bad. If it was really that easy everyone would be wearing those belts LOL. Never have liked seeing people try them. Such a waste of money in my opinion. Shakes are the way to go.
I don't necessarily know what the worst is but I'd have to agree that the belt is up there. It reminds me of the old newsreels you'd see sometimes with a fat guy strapped to a belt that just shook his stomach. It's kind of funny that people fall for it yet sad at the same time.
In general, I'm very skeptical about anything that's advertised to help you lose weight. To me it's the like the advertiser is shooting fish in a barrel. Nearly everyone (even people 10 lbs overweight) is self conscious about their weight and the advertisers play on that. I hate seeing any one taken advantage of even moreso when false promises are made.
I've never heard of Skinny Fiber. FWIW if you eat anything with enough fiber you're gonna continously use the bathroom and thus lose weight.
I'm very skeptical of any diet pills. Most of the ads seem to be centered around the premise that you can "take our magic pill, eat what you want, and still lose weight". It doesn't the work that way.
When I was much younger (late teens) I took Stacker 2 before the they banned it (it's since been reformulated and is now called Stacker 3). It contained an ingredient that messed with your heart rhythm or something like that. When I took it I lost quite a bit of weight but it was practically speed. As soon as I stopped taking it I put the weight right back on.