When I feel the need to burn a candle, I have been using the bird safe beeswax candles put out by "The Birds and the Bees," which are available through avitec.com. They have no added scent, but beeswax has a nice scent in itself.
I have also occasionally used incense sticks, which I do not light, but just prop a bunch in a glass or jar where they give off a subtle scent. I especially like the Sai Baba Nag Champa incense. This stuff will give a nice scent to a room without burning anything. When the sticks dry out and no longer give off scent, they can just be replaced with a fresh batch. Doug, do you think something like that might satisfy your wife for her office area?
Any feedback from anyone on whether the non-burned incense stick idea would pose a problem for the birds?