So, remember the words of Jesus-
“Moreover, when you fast, do not be like the hypocrites, with a sad countenance. For they disfigure their faces that they may appear to men to be fasting. Assuredly, I say to you, they have their reward. “But you, when you fast, anoint your head and wash your face, “so that you do not appear to men to be fasting, but to your Father who is in the secret place; and your Father who sees in secret will reward you openly. (Matt. 6:16-18)
When they smear the ashes on your face to disfigure it, wash them right off because the last thing you want is anyone having any hint that you’re giving something up. That’s just piety for show. Let your pious deeds be private deeds so that they’re really done for God and neighbor and not so you can be seen doing them.