Here's what I did.But bear in mind that I don't grow heavy indica varieties, which really do stink. You could try this quick, cheap and dirty trick I came up with. Go to Walmart and buy a cheap 9" table-top style fan, (or bigger if you think you need it) that allows you to pivot the fan, so that you can have a flat, horizontal, table-top surface, with about 3 inches of plain air on th to lay an 9"embroidery hoop that you have filled with fish-tank charcoal (also at Walmart). The embroidery hoop is used to hold panty-hose or other stretchy, fine mesh, with the charcoal inside, then stretched over the OUTSIDE of the embroidery hoop (The hoop just hold the panty-hose open, to hold the charcoal, nice and flat (about 1/2" thick, so the air can get through it- perhaps you could use more.

Let the fan live in your plant room on the floor and have the air moving up towards ceiling and this through the charcoal. Just having the air in the room pass up through the charcoal does a pretty good job. I don't notice my girls really stinking until a few days before harvest, and even then, it's not bad. Then again, I'm not trying to hide this from my parents. I am the parent!

Every month or so, I wash the charcoal (leave it in the hoop and pantyhose to do this) with plain water running through it, to remove anything that is clinging to the charcoal. Let it dry until it isn't drippy and put it back where it was on top of the fan. Presto! Clean air!