The description of Sanctify is,
Food and water you hold in your hands while you cast this spell is consecrated by your deity. In addition to now being holy or unholy, the affected substance is purified of any mundane spoilage.
I’m curious as to whether this can be used to desalinate a cup of water the cleric is holding. From what I can tell, that is dependent on what is included in mundane spoilage
Mundane has two definitions, one being a synonym to “dull, boring,” and one being
of this earthly world rather than a heavenly or spiritual one
Using the second definition, desalination would be considered “mundane”. I’m not sure if salt water could be considered spoiled, though.