Weight loss shorts

I’m not an expert in these matters, but it seems doubtful to me that wearing a certain piece of clothing could actually help anyone lose weight. It’s possible that wearing shorts or shirts that make these kinds of claims helps people sweat more, and thus lose water weight. But it seems to me that this would be only temporary, and that any weight lost would be gained back by simply re-hydrating oneself.
Weight loss shorts:

Weight loss shorts pictured: North American Healthcare Slimming Sauna Shorts