I am a big fan of active carbonized filters (9mm, 6mm) and especially Vauen filters. Here is something I found on their website that goes into some good detail.
finally tried the 6mm version. It was able to filter out the smoke. did prevent me from tongue bite, i was puffing like a choo choo going up hill.
But it actually got stuck in my pipe stem, the papers swelled up big time. had to rip it out using tweezers and alot of time. Did not have much in the way of charcoal inside it.
Have you considered Savinelli filters. Trouble free. Caveat: I use them in Savinelli pipes...so have no experience with other makers. BTW the filter is the same diameter at both ends. Others may not & that may be the stuck issue?