I put in a little StopLeak PS fluid into my PS reservoir a while back to hopefully stop my rack from leaking. It worked, though my steering wheel has gotten a little harder to turn (not much, so I'm not that worried about it). I need to replace my entore steering system sans wheel anyway and I figure reconditioning the seals bought me another couple months at least.

BTW: NOT recommending that anyone do this, the only reason I did was because my boots were held on by bailing wire when I bought the car, so WTFever, right?