Nor have I, but I thought the Orthodox Wiki entry for “Rosary” opened on an interesting note:
The rosary was originally an Orthodox form of prayer that was later adopted by the Roman Catholics. It has since fallen out of common practice in the [Orthodox] Church.
It is interesting.

I don’t know how accurate the claim is.
But we always immediately have to make assumptions to make these little snippits of information fit. We know Marian devotion pretty much originated in the east and spread westward.
Worth a study, but it is my understanding that the rosary began as a repetition of PaterNosters. If
that is true, then it would originated in the east as a repetition of 150 Our Fathers. And if
that is true then the origin of the rosary is not associated with the cult of Mary in the east (nor in the west for that matter).
Now I can see the possibility of that, but I have never seen it discussed that I can recall.
I really don’t think of a repetition of 150 Our Fathers and a repetition of 150 Hail Mary’s as the same chaplet. One can grow out of the other perhaps, one can be created in imitation of the other, but they are not really the same chaplet, as far as I am concerned.
So what is meant by such a claim? Does it mean that the rosary first transformed into 150 Hail Mary’s in the east? I am open to correction but somehow I doubt that. (If I should hazard a guess I would bet it first happened in the early-to-mid Medieval period in the Carolingian empire somewhere.)
It’s more complicated than it at first would seem.
Anyway, the distinction remains, it is not a liturgical practice anywhere, east or west it is a private practice, probably a response to the need of illiterate and semi-literate devout laity to express their heartfelt devotion and seek divine assistance or forgiveness.