I checked out the following on Snopes.com (rumor/truthiness tester) and they said it hadn't been proved nor disproved - so why not try it??

"To stop night time coughing in a child (or adult), put Vicks Vaporub generously on the bottom of the feet at bedtime, then cover with socks. Even persistent, heavy, deep coughing will stop in about 5 minutes and
stay stopped for many, many hours of relief.  Is more effective in children than even very strong prescription cough
medicines.  In addition it is extremely soothing and comforting and they will sleep soundly.
This guy on A.M. radio talked about why cough medicines in kids often do more harm than good, due to the chemical makeup of these strong meds. It was a surprise finding and found to be more effective than prescribed medicines for
children at bedtime, in addition to have a soothing and calming effect on sick children who then went on to sleep soundly."

I'd love it if other Moms would try this and let me know. We don't have colds nor coughs yet (amazingly!) but if someone out there does, and trys this, please let me know how it works. Thanks - anything to get away for cough meds!