Air Fresheners that use Scented Oils

I use plug-in Air Fresheners with scented oils, such as Airwick. Since they are oil based, does this oil accumulate in my carpets, walls, etc over time? I use the 1.42 oz refill and replace it perhaps every 6 weeks. So where does this 1.42 oz of oil go once it disapears from the bottle?

Thanks.