The problem is doing it that way is that the Escape Artist (or Strength check) DC reads funny: is it DC 18 or DC 19 to escape a single veil? In post 1370, it seemed like the DC to escape one veil was supposed to be DC Y, but then the extra sentence made it DC Y+1. It's just a little harder to divine the intent of the rule.
Should we specify that veils are cut via a sunder attempt? That's somewhat standard in this type of situation. Then no AC is required. I'd go with 5 hp, damage taken by the Maiden, or else 10 hp, no damage taken by the Maiden (like a roper's strands). Hardness can be set when we do the Steel Cloth ability. What do you think?
I'm not sure how you got confused when the description says the bonus applies if the Veiled Maidens "entangle an opponent with more than one veil". It's even in a separate paragraph!
As for the Sunder attempt, I guess it makes sense, although I'd still like to leave them an AC so they can get shot through using ranged attacks.
Regarding the HPs and Hardness, I was thinking 2 hp like a light blade or inch-thick rope. If they are fairly easy to cut once you get through the "steel cloth" hardness it'll make for a more dramatic "being entangled then cutting yourself free" encounter.
How's this revision...
Entangle Weapon (Ex): A Veiled Maidens can ensnare an enemy of up to Large size by succeeding at a melee touch attack with its veil. The enemy becomes entangled and can only move within the limits of the veil's W ft. reach. If the entangled creature attempts to cast a spell, they must succeed at a Concentration check or the spell fails (DC 15, or DC 20 for spells with a Somatic component).
Furthermore, if the enemy is carrying a weapon (or similar implement, like an instrument or wand) the veil binds the weapon and prevents the enemy from attacking with it or otherwise using the object. If the enemy wields multiple implements, the Maidens can only entangle one of them for each veil they hit with, and must choose what weapon they entangle when making the attack.
An entangled enemy can escape a single Veiled Maidens' veil by making a DC 18 Escape Artist check (or DC 22 Strength check) as a full round action.
If the opponent is entangled in more than one veil, the enemy only needs to make a single Escape Artist or Strength check to escape, but the DC to escape is increased by the number of veils entangling them (e.g. +3 DC for being entangled in three veils).
The enemy, or an ally of theirs, can also cut through a veil using a slashing or piercing weapon (AC 20, hardness 10* [
?], hp 2). This frees the entangled enemy from that veil, but the veil immediately reforms.
*This hardness is due to the Maidens' steel cloth ability.