A friend in Calgary reported hearing that cookie-scented bus stickers were removed from the Calgary bus system, due to "old people complaining and because apparently it's cruel to remind homeless people they can't afford cookies."
Having been unable to confirm this, I suspect this is a misreporting of this San Francisco story.
The intention of the California Milk Processor Board was to get people thinking about cookies, and thus milk, but they met with complaints from anti-fragrance groups, anti-allergy groups and anti-obesity groups and the scent-strips were removed on Tuesday.
Regardless of the odd logic of advertising an associated good (as opposed to an associated feeling or emotion) in the hope that it is twinned with your product in the consumer's mind, this just goes to show that how ever you dress it up interruptive advertising is interruptive. People don't like it.