This is a definitive post on why this item is either poorly designed or poorly described.
Corset of Dire Witchcraft
Aura moderate abjuration; CL 6th
Slot body; Price 22,000 gp; Weight 1 lb.
This slimming garment is fastened with laces, buckles, and buttons and reinforced with ribs of leather or bone.
A corset of dire witchcraft grants a +4 armor bonus to AC. If the wearer is a witch, each day when she communes with her familiar to prepare spells, she may enhance one hex she knows, increasing its caster level by +2 for 24 hours. This enhancement ends if the corset is removed or if she uses it to enhance a different hex.
The issues arise in the second and third sentences of the second paragraph in the item description where it indicates:
A) She may enhance one hex she knows
B) Increasing its caster level by +2
C) She may end the enhancement by choosing to enhance a different hex.
All of these issues hinge around the fact that they choose to enhance the CASTER LEVEL of the hex. Are you aware of how many of the witch's hexes are affected by caster level? 1. That's right, 1.
Healing* (Su)
Effect: This acts as a cure light wounds spell, using the witch’s caster level. Once a creature has benefited from the healing hex, it cannot benefit from it again for 24 hours. At 5th level, this hex acts like cure moderate wounds.
This might be reasonable if witches couldn't just pick up CLW and CMW as spells by level 5 anyway.
For those of you who want to argue this point, technically the Major Hex, Major Healing and the Grand Hex, Dire Prophecy are also affected by caster level. However, after doing a little research it's fairly easy to discover that Major and Grand Hexes are not the same as regular old hexes. The feat Split Hex is very careful to differentiate the two. Also looking at the witch class feature Major Hex it says "Starting at 10th level, and every two levels thereafter, a witch can choose one of the following major hexes whenever she could select a new hex." Grand Hex has similar language.
It's pretty clear that Hexes, Major Hexes, and Grand Hexes are separate and distinct, not simply the same mechanic repeated with increased stats as your level increases. Once again, this leaves us with 1 Hex.
Some others have argued that several of the hexes mimic specific spells and are therefore affected by caster level. Well if you actually read the whole hex description instead of just clicking on the link to the spell, you would see that in every single case it alters the mechanic (usually duration) that is affected by caster level so that it is now dependent on something else, usually level or witch level.
Some argue that it is still not entirely useless because abilities such as Flight or Evil Eye get bonus effects the higher level you are. Evil Eye gives the target a -2 debuff through level 7 and increases to -4 at level 8. They say that obtaining this item at level six would allow you to get this increase early. This is not the case. Evil Eye states clearly that it increases at 8th level, not caster level, and while caster level is based on character level, the reverse is not true. Besides, what 6th level character can afford a 22,000gp item anyway?
In essence, as written this item is exactly as useless as you think it is. Further it is pretty easy to conclude that there is a typo in there somewhere. The item allows you to choose which hex gains the enhancement but there is only one hex that it actually affects so what is the point of that statement? Why not just list the healing hex specifically in the item description?
The only reasonable conclusion is that either they meant something other than caster level, or the whole bit about choosing which hex and the effect ending and all of that was meant to be written as "This affects the hex Healing".
So if you are not a witch with this specific hex, do yourself a favor and just go with bracers of armor, at least you can add enchantments and stuff. If you actually are a witch with this specific hex, adding 2 to the caster level of CMW ceases to be useful as soon as your caster level reaches 10 from other sources and lets be honest, plus 2 hp healed on an ability that can only be used on the target once per day is not worth what you are paying, so do yourself a favor and go with bracers of armor.
