Old paper rescue?

I have close to 500 sheets of Kodak Polycontrast III RC that's got a use-by date of 2001. It's badly fogged, except at the very edges. Is there anything that would eliminate the fog, or at least reduce it to an acceptable level (I've used other out-of date papers for negatives with some success, but never ones this bad) even at the expense of speed or contrast? I'd really hate to have to toss the entire batch of it.
I've seen benzotriazole suggested. Any others?

Benzotriazole would have been my suggestion.