The discussion from RS 100-12 expands to consider how the Precious Blood is offered to the laity. It should be illustrative to consider these methods in light of clergy receiving Communion.
[103.] The norms of the Roman Missal admit the principle that in cases where Communion is administered under both kinds, “the Blood of the Lord may be received either by drinking from the chalice directly, or by intinction, or by means of a tube or a spoon”.[GIRM 245] As regards the administering of Communion to lay members of Christ’s faithful, the Bishops may exclude Communion with the tube or the spoon where this is not the local custom, though the option of administering Communion by intinction always remains. If this modality is employed, however, hosts should be used which are neither too thin nor too small, and the communicant should receive the Sacrament from the Priest only on the tongue. [Cf. GIRM 285b & 287]
Intinction does have the advantage of not giving up too much control, hence this directive:
[104.] The communicant must not be permitted to intinct the host himself in the chalice, nor to receive the intincted host in the hand. As for the host to be used for the intinction, it should be made of valid matter, also consecrated; it is altogether forbidden to use non-consecrated bread or other matter.
And this last piece removes the possibility of intincting a non-consecrated material (like rice bread) with the Precious Blood for a communicant with both a severe allergy to gluten and a substantial skittishness about receiving from the Cup.