there is no such thing as “unconsecrating” the Body and Blood of the Lord. As long as the sacred species are recognizable as still containing the physcial attributes of bread and wine the Real Presence remains, that is, their ontological substantial character as the Body, Blood, Soul and Divinity of Our Lord remains. Once they have deteriorated through digestion, solution or other means so as to no longer be recognizable as bread and wine in the physical sense, the Real Presence no longer remains.
If you are asking what should be done with a host that is dropped or regurgitated and cannot be consumed, is it is soaked in water until it is no longer recognizable as bread and the contents poured down the sacrarium, or directly into the earth.
If the priest is purifying the sacred vessels as he is supposed to all the fragments from the paten and other vessels are carefully wiped into the chalice, and when the water is poured in to begin the purification, are swallowed when he swallows that water, and the chalice then purified.
if the various vessels are regularly being returned to the sacristy in your church without being purified properly you need to bring this to the pastor’s attention immediately, and if he takes no action, to the bishop.