My parish priest sometimes asks someone from the congregation to help out with Communion on an ad hoc basis. Also the lay ministers come up to the sanctuary when the priest is breaking the host, the priest gives the chalice with the Precious Blood to one of the extraordinary ministers who receives from it and then passes the chalice to the next one, and they purify the vessels afterwards. Are these practices acceptable?
In answer to your first question, the Vatican’s instruction Redemptionis Sacramentum (2004), after saying that an instituted acolyte is an extraordinary minister of Holy Communion, adds: “If, moreover, reasons of real necessity prompt it, another lay member of Christ’s faithful may also be delegated by the diocesan bishop, in accordance with the norm of law, for one occasion or for a specified time, and an appropriate formula of blessing may be used for the occasion … Finally, in special cases of an unforeseen nature, permission can be given for a single occasion by the priest who presides at the celebration of the Eucharist” (RS, n. 155).
Thus the priest who celebrates the Mass can designate someone to assist with Communion for a single occasion “in special cases of an unforeseen nature”.
This would be the case, for example, when there is a large congregation and there is no other minister of Communion present, whether ordinary or extraordinary.
So your priest is justified in asking someone from the congregation to help out on a particular occasion, but this should be truly exceptional.
After all, the task of distributing Communion requires specialised training, so asking someone from the congregation who does not have this training to distribute Communion should be a rare occurrence.
As regards when the extraordinary ministers are to come forward the General Instruction of the Roman Missal (2012) says: “These ministers should not approach the altar before the priest has received Communion…” (GIRM 162).
So the extraordinary ministers should not go up to the altar at the breaking of the bread. If they go up on to the sanctuary at this time but do not approach the altar itself this would seem to be acceptable.
In this way they can go forward to receive Communion as soon as the priest receives it, without delaying the Mass.
It is not proper, however, for the ministers to hand the chalice, or the ciborium for that matter, to one another after they have received from it.
In a special paragraph for Australia the General Instruction says: “It is not permitted for the faithful to take the consecrated Bread or the sacred chalice by themselves and, still less, to hand them on from one to another among themselves” (GIRM 160).
Related to this is the criterion that the priest should give the chalice or ciborium directly to each of the extraordinary ministers for distribution to the faithful (cf. GIRM 162).
Finally, it is for the priest himself, a deacon or an instituted acolyte to purify the vessels after Communion.
This is never to be done by extraordinary ministers. The General Instruction says: “The sacred vessels are purified by the priest, the deacon, or an instituted acolyte after Communion or after Mass, insofar as possible at the credence table” (GIRM 279).
As the General Instruction makes clear in other paragraphs, if there is a deacon present, he is the one to do the purification; if there is an acolyte, he is the one to do it or to assist the deacon or priest; and if neither of these is present, the priest does the purification (cf. GIRM 163, 183, 192, 279).
I take advantage of the opportunity to say that if there is any Precious Blood remaining after Communion, it is the priest, the deacon or the instituted acolyte who is to consume it: “Whatever may remain of the Blood of Christ is consumed at the altar by the priest or the deacon or the duly instituted acolyte who ministered the chalice” (GIRM 284, b).
If there is no deacon or acolyte, “the priest himself immediately and completely consumes at the altar any consecrated wine that happens to remain” (GIRM 163).
Naturally, if there is a large amount remaining it would be opportune for the extraordinary ministers to assist him in this. The priest should not consume a large amount on his own for obvious reasons.