Braxton's quickie for the day...
Email question: Should the positive connection feel different from the negative connection?
Welcome to The Great Deception! The color coding on TENS lead wires means nothing...due to the fact that we are talking about alternating current. With AC, there is no dedicated positive or negative because the polarity is constantly changing.
With direct current, electrolytes tend to concentrate around the poles, which is not a great thing for your body, hence the switch to AC many years ago.