Some relatively cheap alternatives, (excluding the carbon air filter), would be to get about 3 cups of coffee grinds, 1/2 cup vanilla extract, and a cup of ground cinnamon and place them all (after mixing) in a few coffee filters. Then take a rubber band and seal the filter so that nothing falls out, then fasten them onto the top of a ceiling fan and turn it on. It masks the skunk smell extremely well, so long as there arent many plants growing. Another alternative would be to actually make your own electrostatic negative air ioniser with rotating ion thrust emitters, sharper image style, if you would like to do that pm me and i'll send you the schematics and give you any other info you may need to build it.