Well, the truth is, yes. But only one day a year. And that day is today, the Solemnity of Saints Peter and Paul.
Here's what the enchiridion of indulgences says:
N. 17. Christifidelis qui pietatis obiecto (crucifixo, cruce, corona, scapulari, numismate), a quovis sacerdote rite benedicto, pia utitur mente, consequitur indulgentiam partialem.
"The faithful who make pious use of a devotional object (a crucifix, cross, rosary, scapular, or medal), duly blessed by any priest, gain a partial indulgence.Si autem pietatis obiectum a Summo Pontifice aut a quolibet Episcopo fuerit benedictum, christifidelis, eodem obiecto pia utens mente, assequi potest etiam indulgentiam plenariam die festo SS. Apostolorum Petri et Pauli, addita tamen, qualibet legitima formula, fidei professione.
"If however the devotional object was blessed by the Supreme Pontiff or any other bishop, the faithful, making pious use of the object, on the feast day of the Holy Apostles Peter and Paul, can gain even a plenary indulgence, having added the profession of faith according to any legitimate formula."
So if you have a rosary blessed by the Pope or any other bishop, or indeed any devotional object so blessed, today is the day to pray it or pray with it.
The gaining of plenary indulgences is, of course, subject to the normal conditions, namely being in a state of grace, confession and Holy Communion (usually it is said in plus or minus seven days), detachment from sin, and prayers for the Holy Father.
If you find the doctrine of indulgences confusing, you're not alone. Click here for my best attempt to make sense of it.