This is taken from perhaps the most spiritual blog on the internet the Vultus Christi blog.
The offering of the Precious Blood of Christ for the Holy Souls is a mighty form of intercession on their behalf. Given that I am a firm believer in the value of repetitive prayer, of simple invocations repeated over and over again in the form of a chaplet or rosary, I began to pray for the Holy Souls in this way. Readers of Vultus Christi may want to make this prayer their own during the month of November, even on a daily basis. It is prayed on an ordinary rosary.
On the large beads:
V. Eternal Father,
I offer Thee the Precious Blood of Thy Beloved Son, Our Lord Jesus Christ,
the Lamb without blemish or spot (1 P 1:19) –
R. For the refreshment and deliverance of the souls in Purgatory.
(One can add here, especially those of my family, or of my ancestry, or of priests. The Holy Spirit sometimes moves one to pray for particular groups of Holy Souls.)
Ten times on the small beads:
V. By Thy Precious Blood, O Jesus –
R. Purify and deliver their souls.
After having said five decades, one concludes with:
Eternal rest grant unto them, O Lord.
R. And let perpetual light shine upon them.
V. May they rest in peace.