Two stories, the first apocryphal and possibly true, the second reliably accurate in all details:
It was Ash Wednesday, and the new pastor had forgotten (or never known) to save palms from the year previous to use for the mixing of ashes with oil. Out of necessity, he burnt a pile of papers from the recycling bin in his office and mixed them with cooking oil from the church kitchen. The mixture was of a passable consistency, so he went ahead with using them for the service, only to observe, to his horror, that as he applied the ashes to the foreheads of his parishioners, the mixture of office paper and oil had a sufficiently acidic quality to actually burn peoples foreheads ever so slightly. Talk about burning the sign of the cross into our heads and minds.
At a rural parish I served in southern Minnesota, the president of the congregation pulled me aside the week before Ash Wednesday and said, "Just so you know, we don't do ashes for the Ash Wednesday service." Confused, I asked him why, and why they held the service if they didn't do the imposition of ashes.
Apparently their previous interim pastor, a seminary student, had also not thought to provide ashes prior to driving out to the church for the service. So in haste on a Wednesday afternoon, she too had decided to burn some paper in the sacristy and try to use the ashes for the evening service. Two problems. First, this was one of those old wooden rural churches that has two small rooms off to the side of the altar, one located behind the organ, a kind of office, the other a small sacristy for the pastor to dress and prepare for service. Each of these rooms had false walls but no ceiling. Second, there was an updraft from the cold winter wind buffeting the church.
So when said interim seminarian lit the paper on fire and set it in a bucket to burn, it caught an updraft, shot straight through the missing ceiling of the sacristy and up into the rafters of the wooden church. The ushers, just arriving for evening service, witnessed a flaming ball of paper rising up out of the sacristy and into the wide open space of their beloved building. Imagine! Thankfully, nothing caught fire, the paper descended in ashen form, and from then on, the church decided to have a policy of no ashes on Ash Wednesday.
Assurance from me that ashes would be mixed and prepared elsewhere prior to the service alleviate their concern somewhat. So it goes.