Christians receive ashes, as a sign of mortality and repentance. As for the mortality aspect, is it not akin to the impermanence that Zen Buddhists practice?
Various Christian denominations impose ashes on the forehead with these words spoken, or some variation of them, from Genesis 3:19:
Remember that you are dust, and to dust you shall return.And then many walk around the rest of the day with ashes on the forehead, sometimes in the shape of a cross.
For me, it typically raises a quandary: wash them off or not? In other words, am I "bragging" about some sort of piety that I do not possess? Jesus warned against such strutting. But eventually the ashes need to get washed off, lest one's pillow become all ashy.
Is this a bleak day, a somber reminder of our mortality? I posit it should not be. I further suggest that Buddhists among us (sometimes I strut and pretend I am one, though "practice" is the only membership card, is it not?) would smile. They would not have to say anything.
A mindful Ash Wednesday (or Ash Monday, Ash Tuesday, Ash Thursday, Ash Friday, Ash Saturday, or Ash Sunday) would be occasion enough to smile.