Oi!
I am using it, and also have used the 'other' one that sounds like it [but I can't remember the name...........Ah! Bio chem Zorb, I knew if I sat here long enough I would remember. My LFS said I should always have one and it seems not to hurt [who really knows about these things?]
I did ask a supplier once what would happen if I don't rinse it first before I put it in the filter, he said 'nothing much really' so I haven't rinsed them for the last 3 times to [again] no noticable effect.
I never could stand watching the bag 'stuff' deplete by a third when I rinsed it. The supplier said that the 'dust' isn't that harmful and once it stops 'working' it will be coated with ditritus anyway. The dust just seems ... well dusty, but it's the same as the contense of the bag, it's just that it goes through it.
When I put it in I turn off the filter for a few minutes so the bag can wet, after I turn on the filter there is a 'bit' of a cloud, but nothing more than adding water into the filter and watching the 'gunk' flow out.
Cheers!
nigle
!~!