When I was younger (30 years ago) and had little cash, living in beautiful rain-soaked Dublin, Eire, I used to soak my chains in paraffin oil or even white spitits. I then heated up some vaseline in an old tin and immersed chain. The heat allows the vaseline to soak right into the bits when ordinary oils don't get to. Coll off and wipe dry with a rag. Now I ride in warm dry weather so no chain problems. I have a spare bike for the rain!
Hope this helps
r