My vote goes to ""No WATER"". I have been impatient a couple of times and put my films back on without waiting for the water to completely dry. The rubbers ended up with patches that are less sticky and could not be removed.
So my clear films only go onto dry rubbers and i find the longer they stay on the stickier the rubbers then are.
What would the explanation be for why having water in between the sheet and rubber would be better than just the sheet and rubber? It is simply cargo cult science/old wives tales/voodoo people make up. As long as the sheet is adhering to the rubber and air cannot interact with the rubber surface, it is adequately protected.
On the other hand having water, especially if it is tap water which can contain mineral impurities on the rubber and evaporating off over time from the sides, will leave deposits on the rubber and the moisture will affect the wood of the blade if kept in an enclosed case.