The thing with these approaches you suggested is the one I mentioned in this comment: http://www.question2answer.org/qa/55363?show=55365#c55365
If you use a layer then you shouldn't get rid of the elements in the question lists. Both plugins do so, which means each page with hidden questions becomes smaller in size. As I mentioned in my post, a better approach is to display the question but don't allow the user to read it (in any way). That way you won't face the awkward situation in which you browse a question page and you see no question in that page (because it is full of hidden questions that are not being displayed at all).
The only way to solve this is by hacking the core, which is explained in the related question in my answer. I'd still wouldn't advise that, though.