I found the majority of the offending material inside the sleeve of the positive post's sleeve and on the screw's threads, the negative post also but lesser.
I twist up a piece of paper towel and keep twisting it into the sleeve till it comes out clean. I was really surprised just how dirty it was after thinking my initial cleaning was good enough.
I twist up a piece of paper towel and keep twisting it into the sleeve till it comes out clean. I was really surprised just how dirty it was after thinking my initial cleaning was good enough.