Q: When the priest sprinkles the people with holy water, does a deacon have to hold the bucket?
A: Not really. The missal says nothing about who holds the bucket, so it could be a deacon, a server, or the priest himself. However, in the Ceremonial of Bishops, a deacon holds the bucket while the bishop blesses the water, and deacons accompany the bishop when he moves through the church to sprinkle (133). Logically, one of them would hold the bucket, but the Ceremonial doesn’t specify that.