Vague or Ambiguous Sentences

Recently my professor in my Bio10 class showed us a short video called "Here Be Dragons". It is basically a video introducing the basics to critical thinking, while putting down "psuedo-sciences". One part that really caught my attention was when the host was talking about products that aren't FDA approved. Basically, it is legal to sell any product as long as its not blantently dangerous and doesn't claim to diagnose, treat, cure, or prevent any diseases. This is where the vague statements come in. Manufacturers of these products use vague statements on purpose in order to get around laws which wouldn't allow them to sell their products in the first place. An example mentioned in the video was about herbal dexocifications. "Herbal detoxification restores vitality." To the average person, this statement has enough merit to pass off as true, when it is in fact quite useless to use for reasoning. What is detoxification and in what way would it restore your vitality? Purposely vague statements like this accounts for billions of dollars spent a year on useless products. Watch out for these in advertisements and commercials people!