EXTRA: LaborratoryG 5

Rosaries are the glowing Blue Crosses (https://vampire-survivors.fandom.com/wiki/Rosary) that screen wipes enemies

If you have already collected enough the achievement will unlock upon finishing a new run.

They are a random drop so the best method of farming is just playing a map/character you are confident with and selecting endless. Approximately 40 minutes of farming should be enough to go from 0-33.

The achievement should unlock once you end the run after getting 33.