Here's a thought, I was wondering if anyone else thought it was a good idea.
In the stats, under the Hides Tab, add a section showing all of the hiders Challeges caches. and for each one, show a list of users who have posted a 'found it' but do not qualify. Just like the project-gc greasemonkey script shows at the top of the page when you look at each challege cache, but here it would be all in one place.