You want to make certain that you get the chain temperature above 212F so that the water vaporizes away. Otherwise it will take a long time for the water to evaporate out of the tight spaces in the chain; think of water trapped between two panes of glass, it will sit there for weeks. The suggestion to rinse with alcohol is a good one but then the alcohol will need to be gotten rid of somehow. I just put my chain into a 250F oven for 20-30 minutes. I have never had any rusting occur.