We bought some of those beads that you put in the air injector/blower compartment.
When the blower is running, there is a faint smell, nothing very impressive so far. The beads are overpriced in my opinion (about $7.00 for a pack of 2, if I recall). One scent that they have that we didn't try yet is eucalyptus, maybe that would have been nice when I was recovering from pneumonia a few months ago. But I certainly can leave the scent thing behind.
Brewman