Orb of Annulments: question and feedback

It seems it is pretty rare. I had a single one of this while I have like 30 chaos orbs.

Chaos replaces a mod, annulment removes.
But while it can be used on magic items, can they be used on unique? I guess not, because otherwise we would see some impressive unique juices.

But does it at least removes corruption or fragments?
I totally bricked an item. I wanted to use fragment in hopes to save a +3 melee skill.
Obviously it didn't. Would have been great to clean that thing off.

Would be good to remove corruption mod.
- its rare enough to do that
- and in the currency tab its on the opposite side of vaal orb anyway

Or is there some weird mechanic I should be aware of?
Not as if it matters because the rarity of it wont let me to play RNG spins.

it has higher value for good reason. it has its purpose. and its not suitable for low tier crafting.

ok... keep your secrets...

So wehy is it so valuable?
It just removes a RANDOM mod.
That is more than likely you want to replace. So why is it better than a chaos orb?

TBF I just realised I vaal-d my necklace, so I cant put distilled emotions on them anymore.
For a n00b like me it would have more value to just remove the corruption from it, because now I have to find a good necklace first when I finally get my delirium mats.