Another sacramental that is connected with the devotion to the Precious Blood of Our Lord that our Mother, Holy Church gives us is the red cord or sash of the Precious Blood.
The Roman Ritual gives the following blessing:
BENEDICTIO FUNICULORUM ET VITTARUM
Vittæ fiunt ex lana rubei coloris, quæ, si exterius a mulieribus ferantur, a sinistro latere pendent. Funiculi pariter ex lana rubea conficiuntur.
V. Adjutórium nostrum in nómine Dómini.
R. Qui fecit cælum et terram.
V. Redemísti nos, Dómine, in Sánguine tuo.
R. Et fecísti nos Deo nostro regnum.
V. Te ergo quæsumus, tuis fámulis súbveni.
R. Quos pretióso Sánguine redemísti.
V. Dómine, exáudi oratiónem meam.
R. Et clamor meus ad te véniat.
V. Dóminus vobíscum.
R. Et cum spíritu tuo.
BLESSING OF CORDS AND SASHES OF THE PRECIOUS BLOOD
The sashes are made of wool dyed red; and if they are worn outwardly by women they ought to hang on the left. The cords too are made of wool dyed red.
V. Our help is in the name of the Lord.
R. Who made heaven and earth.
V. You have redeemed us, Lord, in your blood.
R. You have made us to reign with our God.
V. We therefore implore you to save your servants.
R. Whom your precious blood has redeemed.
V. O Lord, hear my prayer.
R. And let my cry come unto Thee.
V. The Lord be with you.
R. And with thy spirit.
Omnípotens sempitérne Deus, qui Unigénitum Fílium tuum constituísti humáni géneris Redemptórem, ac ejus Sánguine placári voluísti: da nobis tuæ dilectiónis augméntum, et super hos funículos (vel super has vittas) bene + dictiónem tuam infúndere dignáre; ut, quicumque eis cinctus fúerit, suórum delictórum contritiónem in terris habére mereátur, et ab omni carnis labe, cunctísque perículis mentis et córporis liberátus, ad vitam pervéniat ætérnam. Per eúmdem Christum Dóminum nostrum. R. Amen.
Et aspergantur aqua benedicta.
Let us pray. Prayer
Almighty everlasting God, who appointed your only-begotten Son the Redeemer of the human race, and willed to be appeased by His blood; increase our love of you, and be pleased to pour out your blessing + on these cords (or sashes). Let him (her) who is to be girt with one know compunction for his (her) sins in this life, be delivered from every sin of the flesh and all dangers to body and soul, and finally attain everlasting life; through Christ our Lord. R. Amen.
They are sprinkled with holy water.
I have also found the following thoughts on this sacramental:
Cord of the Precious Blood is a pious and efficacious practice recommended particularly to the sick.
To glorify the Precious Blood of our Divine Redeemer and draw down its salutary benediction, is to wear the red cord blessed in its honor.