Fingerprints and smudges are oily and will require some sort of solvent to remove them. There is a product named PEC-12 which should do the trick, but it is expensive. Isopropyl alcohol should be effective, but you'd need to try this out on something unimportant to get your technique perfected. In any case, I would give the film a good soaking in clear water followed by a dip in wetting agent before drying. Distilled water is not necessary provided your water supply is clean, and I'd still use a wetting agent.