Blessing of Households for Epiphany

We were running a bit late for Sunday Mass at our own parish yesterday, so we went to the neighboring one, where Mass started a half hour later. There was a bit in the bulletin about a traditional blessing for one's home on the occasion of the Epiphany, something about holy water and chalk.

I went to Catholic Online but didn't find any specifics. Can anybody clue me in on this?

--Sparki