Dausuul said:
The question is whether enchantment is something that you add to an item, or a process you perform on an item. Residuum implies the former; I prefer the latter.
Then allow me to try a different approach, but with the same end result.
In the
Dresden Files novels, there are three holy swords. These swords each have a nail from the Crucifixion worked into the hilt. They cannot be destroyed, because they are not merely swords; the physical presence of the sword is a pale comparison to the symbolic presence, the Soul of the sword, if you will.
However, the soul of the sword can be stripped away, just like the soul of a mortal can be corrupted.
The main character got ahold of one of these swords, as he was holding it for his friend, the true wielder. Well, the Main Character tried to use it to attack a creature that
he had made a deal with, and he was trying to reneg on the deal; this sword was used to betray an oath. It made the sword inert, because its purpose (A holy sword meant to do just battle against evil) had been corrupted in a selfish manner.
The sword could then be destroyed because it had no more protection; it was just metal because the magic that made it more had been violated.
In another instance, the sword could have been rendered inert after the wielder used it to attack first under a veneer of parlay and peaceful diplomacy.
So, a weapon could be disenchanted if it is used against its purpose (such as a rightful wielder of a
Demon Bane sword giving it freely to a demon). And when it's disenchanted, the power that had enchanted it has to go
somewhere.
If you want to make disenchantment more meaningful because the magical items
themselves are more meaningful, then you should have the ritual to disenchant relate to the item itself. You can't just destroy The One Ring; you gotta take it to where it was forged, in Mount Doom. Etc etc. Disenchanting becomes a quest in and of itself.