Google tells me “An odor is a chemical molecule light enough to be swept around by the environment” and Sleeper’s been hanging out with Daredevil for the last month or so, ergo I’m inclined to think he’s had some practice hiding his scent, HOWEVER I would think the open window and resulting breeze would be detectable by Kaine’s super senses? So he should still be able to figure out something is up.
I will defer to the Watcher though.