It would depend on how you apply it I guess. If you stuff it down a pipe and let air blow over it I dont think It would do much good. As the air wouldnt have time to mix with it before it's blown out.
And the fact that it costs 50 bucks or so to make a scrubber buying your own parts and carbon. You might as well buy a professional built one for 80 bucks and save all the trouble. They do a better job, they last longer, easyer to replace, and less bulky. Kick in the extra 30 bucks and stop worrying.