Cleaning old/dirty negatives.

Just received an envelope containing 6 old negs. from the 1930's.Talk about rough shape.Stains,finger prints & dirt.
Read some of the posts dealing with this issue that suggest either:1.Bath in pure isopropyl alcohol 2.A mix of I.A and photo flow.
Has anyone done this with old negs.?

It depends a lot how bad they are.
Sometimes cleaning with PEC 12 Photographic Emulsion Cleaner is all that is needed.
Re-washing should work, but with old nitrate negatives there's a chance of the emulsion coming away from the base.

If the negs were not well fixed originally then re-fixing and re-washing is an option.

I have had good results in cleaning old negs using a C41 formaldehyde based stabiliser bath.

The link below may be useful

http://cool-palimpsest.stanford.edu/byorg/abbey/an/an26/an26-5/an26-512.html