Note that the title is a completely meaningless pun--the episode has nothing to do with "scents." You need to have a single meaning before you can go for the double, people.
The idea here is that Scrooge and Flintheart are competing in the "Kenducky Derby." The kids come across a showhorse ("Milady") that likes to get photographed, only the owner's going to lose her due to non-payment of bills, so they train her to race in the derby to make some cash.
Can't claim that I was particularly taken with this episode; it's over-stuffed with a lot of incident that never really amounts to much of anything: here's Milady's owner! Here's the, um, evil oat-salesman! Here are the evil weasels (or possibly foxes) that Flintheart hired to steal Scrooge's horse! Blah! It's hard not to feel an overwhelming sense of apathy just thinking about it all.
In the end, Milady doesn't win, because HDL realize that if she did, the evil oat-salesman would get the money, so they get her to stop by making her think her picture's going to be taken. This makes the evil oat-salesman (I won't deny it: I do enjoy writing out "evil oat-salesman") angry, and so he doesn't want her anymore. Which makes no sense, because he never wanted her as a racing horse in the first place; she was just meant to do farm work. But it's an appropriately unexciting ending for a mediocre-at-best (very best) episode.
-Webby looks pretty chic in her racing…hat…thing (you can tell how much I know about horse racing).
-One of the extras in the stands at the race appears to be Grandma Duck.
-I am always amused by the idea of one's domestic animals being "good" or "evil" to match their owners, as Scrooge's and Flintheart's horses are here. Like Battle Cat and Panthor from He-Man.
-Scrooge, on hearing that Flintheart's horse is in second place: "Ha ha ha--number two! An appropriate number for your horse, Flintheart!" Did he just call Glomgold's horse shit?