Presoaking is bad and normally not necessary try alcohol to remove the grease from finger prints a water presoak might not work.
Well, pre-soaking may not be necessary in many cases, but it is certainly not "bad" in any sense of the word. Even Ilford clarified their position on not recommending a pre-soak. They said that they don't recommend it because it's not needed, but it won't have any negative effect if you decide to pre-soak anyway.
For many applications, a pre-soak is indispensable: before developing batches of sheet film in trays to prevent the sheets from sticking to each other, when using SLIMT or any other pre-treatment before developing, to bring Jobo and other large tanks to processing temperature before developing, etc.
@OP,
If you think oil from your fingers is preventing development (i.e., if the fingerprints on the developed negatives are lighter in density), then a pre-soak in water (a rather long one, I would imagine) may help, but I tend to agree with Xmas about trying alcohol. I've never tried using alcohol as a pre-soak, but see no reason not to give it a try; it will certainly remove the oil from the surface of the negative before development. You may have to follow an alcohol soak with a water soak. You'll have to do the experiments.
If, however, the film emulsion was damaged by handling or exposure to finger oil, then there's nothing a pre-soak will do to help.
Best,
Doremus
