This was introduced to me over sixty years ago (holy smokes I'm getting a little in the tooth Haha) any way just plain old vaseline. It's all I've ever used since. Preventive medicine. On the other hand I have reels I've used for decades and used a lot in all kinds of weather and never had them apart and still work as smooth as new. Most reels are sealed very well and keep the dust out that cuts into the bearings and gears. Depending what they were lubricated with at the factory it could break down and lose it's viscosity over time. It certainly won't hurt as Akrisoner mentioned a good cleaning and then lubricate. Any way I swear by vaseline, you don't need to apply a lot, it's water proof and doesn't stiffen up in the winter.