i agree. i wouldn't trust any filter which was washable, much less a carbon one. the $$ spent on Ebay will get you a good 6" inlet x 3-foot tall carbon filter tube made from quality metal, and you can change the carbon in them after long use.
FTV, I run an odor sok and they work very well. You need to make sure you don't have positive pressure in the room, if there are any gaps in the walls etc you will just push the odor out there and bypass the filter.
You can reactivate the carbon in any carbon filter by steaming it.
Odor socks just get thrown in the dryer on hot for an hour or so and are usually good for a couple of grows.