Record archivists use lab grade detergents Tergitol 15 s9 and 15 s3. One attacks water soluble dirt and the other attacks oil based non soluble elements. Mix with DI water.
Look for it at Laboratory Technical supply houses. I bought two pints years ago and have not made a dent in the first pint.
Look for it at Laboratory Technical supply houses. I bought two pints years ago and have not made a dent in the first pint.