I am by no means telling other ministers what to do with their Christian liberty (I know that will be the appeal), but for this former Roman Catholic turned Presbyterian minister, the words of a wise Lutheran pastor capture my sentiments about applying ashes to the heads of Christians (who are adopted sons and daughters of God through Christ) on "Ash Wednesday":
"It isn’t my office to put soot on your foreheads, but to wash you clean of sin and death with the bloodied words of Jesus. It isn’t my office as a representative of Jesus Christ to put the mark of death on you. I’m an 'evangelist,' a proclaimer of 'good news,' Gospel, and a smudge of death is not good news."
Peace, whatever your practice may be.