Alum powder is used in spell work, altar tools, floor washes, amulets, candle magic and spell jars. 

Magical properties:

• Stopping Gossip/Slander: This is one of alum's most common applications. Because it has an astringent quality that "puckers the mouth," it is magically associated with keeping people from speaking negatively about you.
• Protection: Alum has a long history of use as a protective amulet, with practices dating back to ancient Egypt and North Africa. It is used to guard homes against evil spirits and negative energies.
• Cleansing and Purification: Alum is added to ritual baths and floor washes to cleanse the aura and living spaces, removing stagnant or unwanted energies.
• Attracting Luck and Abundance: In some traditions, it is used to attract money and remove financial blockages.
• Legal Work: Alum is sometimes incorporated into spells intended to provide luck or favorable outcomes in legal matters