I’m not sure how it plays out in the Eastern church, but it’s certainly a VERY popular devotion in the Latin churches around these parts. And Latin homes and schools as well (I myself have an icon of OLPH in my home).
Most every church will have an icon of OLPH somewhere, and several of them hold weekly (even twice-weekly) public novena prayers where her intercession is sought. It’s basically a prayer service in front of the exposed Blessed Sacrament, so concludes with Benediction as well.
The service basically consists of the singing of a few hymns, the saying of a few prayers, a reading from scripture and short reflection by the priest, and the reading of some intercessions (there’s a box in the back of the church - people write down their prayer requests for OLPH and put them in, some are read, others are grouped together ‘for all the sick’ ‘for all those in financial need’, things like that)