Roor carbon filter??

i was just looking through the roor section on EDIT lately and ive never asked about it but i thought i would now. im talking about this little glass on glass spherical attachment that im guessing goes in between the bong and the bowl like an ashcatcher?? anyways it says...

"The Roor Carbon Filter Adaptor is designed to house an active charcoal filter to clean the smoke of carcinogens, allowing for a cleaner, smoother smoke.

Activated carbon can be easily obtained in most good aquatic shops at low cost."

has anyone tried one of these? does anyone know what the effects on smoke using something like carbon is? i know carbon filters in fish tanks are used to filter all the shit out and i believe my brita water deals filter has carbon in it too, to filter out chlorine and other minerals and shit in the water. but what the hell does it do when you run some cannabis smoke through it? any help is appreciated.

if you know anything about catalytic converters its the same thing the smoke goes through the carbon acting as a catalyst filtering out....things but if RooR's doing making them for bongs, its probly a good thing

I've tried a friends, and wasn't too impressed - didn't change the flavor at all, just seemed to add more drag. Seems like it might capture some of thc also - Im not sure. The more surface area thats in the way, the more contact surfacethe smoke has and will leave residue on. I'm not doubting that the carbon may filter out some impurites, but it didn't warrant me ordering one for my collection.