What Purification looks like

Purification magic is based on removing impurities, not destroying or vanishing them.  

Purifying Magic

  Removing a magical curse or dispelling a spell has very little visible effect because magical energy is more or less invisible to the naked eye. The magic might make a spark or a shimmer but it disperses into the air pretty seamlessly.  

Purifying Water

  Purifying water with magic will physically remove impurities from it. For drinking water, it is usually best to put the unpurified water into a barrel or vat or something similar and then cast the spell which will cause all the contaminants to leave the water and form a pile.   If sea water is purified, this will create a small pile of salt. If the sea water is dirty, this will create a pile of salt and other things. Hypothetically a second casting of Purification can separate out the salt from the seaweed, dirt, and other non-salt aspects.   If you cast Purification on the sea without putting the water in a container first, the magic won't do anything because it will remove the salt from the immediate water and drop the salt into the sea nearby.   One could have a container nearby to catch the contaminants from a body of water. In this way, Purification can be used to cleanse a tainted body of water, at least in part. A Purifier could take a boat across a polluted river and pull the contaminants into the boat.  

Purifying people

  Purification magic can remove toxins or diseases from a person, but it is not pretty or pleasant. The subject will expel the toxins via urine, vomit, feces, or at the very least, sweat.   This often results in their clothes needing to to be dosed with Purification magic   A low success roll will usually cause toxins to be removed immediately, whereas a higher success roll will give the subject enough time to run to the privvy at least.   Often, temples and healing facilities have a separate room or at least a curtained off corner with some buckets set aside for Purifiction with a modicum of privacy and dignity.   No clothes are soiled if the subject of the Purification is nude.  

Purifying Gross things

  If Purification magic is cast on fecal matter, rotting corpses, or anything putrid, the magic will transform the substance rather than separate out the pure from the impure.   The end result will be something less gross but fundamentally the same as what it was before. For example, poop will turn will be dried out and (mostly) deodorized, ready to be used as fertilizer.   Disease spores or germs will be killed but the substance will still be gross.