the DRE has to have the parent’s permission to allow the children to taste the wine. We practice in CCD with cranberry juice, because has more of a bite than grape juice, and with unsalted wheat thins and oyster crackers, which are very dry, because pastor does not allow us to practice with actual unconsecrated hosts. We strongly urge the parents to allow children to taste wine at home so they do not react. Some children over-react to any strange taste. We also warn parents about the gag reflex. It is hardly reverent for a child to spray the precious blood all over. We also use this as a teaching moment, to say the Catholic Church has not prohibition against wine or any alcohol in moderation, and point out that wine was normal food for Jesus and his friends in their day.
We practice as much as we can, but there is not much we can do to prepare children whose parents seldom bring them to Mass. We do not practice receiving in church, to avoid confusion, but we do practice processing, genuflecting, posture etc. However CCD is primarily time for instruction, not rehearsal. Most of this is the parents’ job, not ours. We also practice receiving both in the hand and on the tongue, but if the children seldom see people receiving on the tongue, it does not have much effect. Most receive as they see their parents or other adults doing. Since at least half the children have parents who cannot or do not go to communion, we have an uphill battle.