Start with alcohol and a Q-tip or odorless mineral spirits/Q-tip. But, it sounds like you have a plated brass ferrule with some corrosion. That green stuff is copper oxides and it has to go. This ferrule style allows access down into the rod blank. Don't drop the Q-tip or let solvent run down into the glue joints.

If the Q-tip/solvent doesn't do it, try a very MILD abrasive. I would use one of the following (in order of aggression) toothpaste, silver polish, brass polish, 0000 steel wool with oil, 1000 grit sand paper and oil. Gently remove the green goo. Stop often to clean out the ferrule and test fit it. DON'T OVERDO! A little tight is better than loose. If you really muddle it up, a new ferrule is cheap and easily installed.

Whether you should lubricate your ferrules is debatable. Personally, I keep mine clean and don't have sticking issues.


Tom