I was thinking that the pearls are nothing more then resin. As we know resin is used under static charge to collect debris just like when you rub anything plastic it has a powerful adhesive affect on almost anything even particles of dirt, ammonia ions, nitrate ions, you name it. Then when you discharged the resin temporarily using a any salts it releases all the collected debris.
The problem comes into play when you don't have a separate flushing location as is demonstrated in the video, this same thing happens in a water softener the resins release all the debris to the drain and get washes before going back into service. However when you use resins in your canister like Ammocarb or ammonia chips, just another name for charged resins, all of the chemicals , toxins, and dirt they collect can and will be released back into the aquarium on the next water change when salts are introduced via your water conditioner like Prime. So I never recommend using resins in any filter except perhaps this one which has a back flush.
Nevertheless too pricey when you can build you own out of an old water softener hooked to your aquarium and home drain system something that I have never tried but would probubly work well.
