Use them for pretty much anything you want, I'd rather the corrupted abbey was a small one though (So more like a chapel than a full on abbey) They tend to be pretty inept at actually locating the heresy, its only when they've found it they are actually good at what they're doing. Most don't have a clue on how to find it, with only the members who live in the larger abbeys actually having methods to properly seek out heresy, The rest just sort of hope for a proper catch. Its more fear than effectiveness that does their work.
In short, sure, as long as the Abbey wasn't very big or anything so the skilled ones weren't there.