i forgot about this post.
i've got them in my bike right now. i can't say either way if they work or not, because i didn't do a before and after test with them.
my bike has no hand-numbing vibrations anyway, and i want to get new grips, so maybe i'll take them out for awhile, and see if there's a difference.
my first bike used to numb my hands, but this one's set up so much better, it could be a multitude of reasons why it doesn't vibrate.
and as a point of reference, or something, i've got a slight case of carpal tunnel syndrome in my right hand from crashing on my skateboard a million times, and from breaking my thumb getting hit by a car 15 years ago.
broke my left radius at the wrist 4 years ago, also skateboarding, almost snapped the neck of the bone off, so that one acts up sometimes.
both of my wrists make this cool clicking noise, too.
but i can ride all day with no problems.