it depends on what you mean when you ask does it work..... will it fix all your problems like they claim no. will it help out kind of like carbon? yes. there are many other chemical media out there.
We used to use Chemipure to "polish" the water when we used UGFs, got rid of the yellow DOC water when water changes weren't enough. I keep it for only occasional use now
It works, and lasts longer than a bag full of the equivalent amount of just plain carbon. But water changes work just as well and do your fish much more good!
I agree, Purigen is superior to Chemi-Pure...I've always wondered if Chemi-Pure isn't just granular activated carbon with little Purigen beads in it.