Re: 2 things I'm wondering about
I'm using a honeywell brand air purifier. It uses a HEPA filter (high efficiency particulate air filter) that removes like 99.7% of stuff in the air. But it is the prefilter, activated carbon, which wraps around the filter that actually removes the smoke smell. I used to smoke in my apartment all the time and I would have the baclony door open (the screen door shut still) and the purifier was on all the time on 'low' but i would put it to 'med' or 'high' when I smoked. No one could ever smell anything from the hookah 30minutes later.
However, smoking in my room where there is not as much fresh air coming in, I found the smoke would settle on fabrics, ie carpets and bedding, and the smell would linger. The living room had wood flooring. After smoking and using the purifier and some air freshner, it would take a few hours for the smell to greatly dissipate and half a day to barely notice it and then a day to not notice it at all. Sorry if this isn't the answer you're looking for, but I think carpets really do absorb a lot of odors.
On the other hand, after taking a big hit and blowing thick smoke into the filter, my friend could not smell anything at all (no smoke came out just air) from the outlet fan.