We have a dog that sleeps in our den. We bought a natural air freshner that helps with the smell. It is in a plastic mesh type bag and it looks like little small rocks are in the bag. It is to help with odors. We keep it out of reach of our dog and kids. We've used it and it helps a lot. It has a hook for hanging and you could also use it in your closets too. We bought it at the Outlet Mall near Gainesville in the Wamsutta store/Linen/Comforterer type store. We bought it last July and is still working fine. You could also try a health food store and see if they carry anything like this. Linen's N Things carries things like that also.
I've also used a small jar with a dry air freshner, someone gave it to me. It looked like someone had made it, it had lace over the top of the jar. It looked like it was some sort of gel. It lasted a long time. You might try some craft stores, where they sell antiques, crafts and homemade type gifts. I'm sure Canton-First Monday Trade Days would have it. You might do a search online for gel air freshners.
I wouldn't recommend the air freshners in the store, we used one and you turn it on and it got too hot and it burned part of the top of our stereo speaker. We learned the hard way, you have to be careful where you place those battery operated air freshners.
You might try potporri (sp?), the dried flower mix. I've used that and they come in different fragrances. When the scent goes away you freshen it by using an oil to pour over it.
I would try a a high quality air cleaner. We have one that is a HEPA filter. They pick up smoke, dust and keeps your air clean also. That should pick up the smell also. The downside of these is that you do have to buy air filters after awhile when they get dirty.
We also have a Rainbow air cleaner that uses water. You can also buy air freshners to help freshen the air. We bought one air freshener, however we didn't get the other scents they offered. We bought it from a Rainbow salesman who came to our house. If you interested, email us and we can give you more info. It is good that you don't have to buy the air filters on a regular basis.
You might want to get some filters that go over your vents for the air conditioning/heating. We had those when we were in a duplex and it really helped. They come in bigger sheets and you can cut them down to the size of your vent. They fit on the inside of your vent.
If you have any questions or need more info, feel free to email me.