I find that plug-in scented oil things can be irritating to my throat. And even if they mask the odor, they won't remove the allergens from the air.

Would Lysol help? I sometimes have a problem on humid summer days with a musty smell in my condo. If I spray lots of Lysol when I leave for work in the morning, it still smells fresher when I get home later in the day. (I'm hoping my almost-finished kitchen renovation will solve or significantly reduce the problem in my case, since lots of old wood cabinets and some moldy drywall were removed.)