Hey,
I have a 97 SC 400 and had the same problem. Tried a few products and never got the results I wanted. Honesetly you should probably just replace them. You can find a decent price on a new or refurbished pair of headlights on e-bay. Got mine for $350 (pair) which to me was well worth it. Made my car look almost brand new. Hope this helps...
J.Wills