Related to the question on whether magnets work or not:
My brother-in-law purchased a magnetic bracelet and swears that it works in making him more 'balanced' and 'stronger'. To prove it's effects he made me stand with my feet about a foot apart and pulled my right arm down and away from me. This caused me to lean over and take a step. Then he put the magnet on my wrist and repeated the experiment. Of course, this time it was much harder for him to pull me over (because I knew what was coming).
Obviously I could have him repeat the experiment in the reverse order on a new person to prove that this 'test' is worthless, but I doubt he will be convinced. Part of the problem is that he'll argue that it works 'for him' and may not work for other people. He also may have a small aversion to me presenting the argument, since agreeing with me would then mean he'd have to admit he was duped.
Putting aside the question of whether I really want to get into this argument with my brother-in-law, is there a simple way to prove to him that the magnet is not making him stronger?