I should make a correction to my post above, after reading Chapter 7 - plainly Heccate's Ozcura-lore isn't quite as faulty as I (perhaps carried away by my theory -rthat happens ) claim - it works well enough for Evelyn to...

(spoiler alert!)

... claim the protection of "sister Ozcuras" to escape being raped by Orcs.  

Which raises an interesting question - if the Ozcuras had known that Evylyn was an escapee, not a prisoner would they still have been obliged to help her? Ozcuras are simple creatures, and the ceremony was basically a magical working. Magic has no interest in faith, or conviction. Rituals done properly must work, like a key fitting a lock. If you went through the ritual you are an Ozcura, or enough of one that it's not done to let thoze stupid orcz grab one of uz!