Interesting! I cannot recall any such marketing materials for Ovaltine. The only reference I can find regarding this strategy is from 2000[0]. Both the drink and the brand, in my experience at least, have always been associated with comfort, family, pajamas and bedtime. I seem to recall "Ovalteeney" being a mild pejoritve to describe those of a quiet/calm nature.
[0] http://www.campaignlive.co.uk/article/ovaltine-target-younge...