Just want to throw another possibility on what the green stuff could be, though the suggestion of brass tarnish is probably more correct, there is the possibility that it could be mold. Really have to get a better look to be sure, but with all organic materials the possibility is always there. A good fungisidal soap will kill the mold, and clean the handle. Mild dish soap with real hot water seems to work ok too. Never read the label on the Murphy's bottle so I dont know if itll kill fungus, but if it does then hey hit all the possibilities with one stone.