Probably best to wait after mass and approach or call to make an appointment. Don’t be like me who just turned up at the church and knocked on the office door with my rosary (I didn’t know how these things went ). Luckily one of the priests staff disappeared with it and came back with it wet saying ‘ I think Father got me with most of that holy water but here you go !’
You can take them with you to Mass and after Mass ask the Priest (or Deacon if there is one present) to bless them. Alternatively, you can drop them off at the Parish office and make arrangements to pick them up later.
Sometimes my parish priest would bless an icon or statue just before Mass is ended. This happens if the icon/statue portrays the saint of the day or celebration. Normally people bring the items to the sacristy or give them to one of the sacristans and that our deacon bless items after Mass has finished.
As a sacristan I get my fair bit of holy water too. Seems like some priests and deacons get everyone wet in the room and not just the person bringing the item and the item itself.
If you have the possibility listen to the blessing. There are a great number of them for example if it is an icon and there is also a different blessing if the Blessed Virgin is portrayed on it.
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