I cannot believe we didn't do this this year...we were over worked and tired and we completely forgot (we forgot St Nicholas' day, too! Grr).
Well, check the blog above, actually Jan. 6th being 12th night is still acceptable to do this.
We usually use regular chalk. Our church doesn't do a ceremony.
Thanks to Easter (a follower of my blog) for pointing out this website on her blog! :))