If you equip it before entering Sharance Maze, all floors will only have two rooms: the entrance and the boss room with the exit to the next floor. You can remove the Rosary after entering and the effect will persist until you leave the dungeon.
Sleepy Grass • Fire Element • Water Element • Wind Element • Earth Element • Protein • Int. Vitamins • Vit. Gummy • Dex. Bottle • Antidote Herb • Para-gone • Cold Medicine • Energy Drink • E. Drink S • E. Drink X • Formuade