Yes, there are pet deodorizing air fresheners that come in a can/plastic jar and are unscented, and that is what I would recommend. Plug-ins get kind of hot, so I make sure they are not close to the crate. I have used the D.A.P plug-ins, never the air freshener kind. Candles create particulates in the air, which is not good in a closed area.
First time Chihuahua owner with many years of dog experience!