Well, here we go with the someone told me . . .
If you put grease on there, that does OK until things get hot (like in the summer time) then it runs and melts off. It is also very greasy, it is after all, grease.
They told me to shoot it with spray paint. It goes one as a liquid, gets into all the nooks and crannies and then dries hard to seal it.
I had a friend that worked on electric fork lifts and they had some official batter terminal protector that he gave me. Spray it on and it foams up, then settles down to a hard, plasticy finish. I have no idea what it is other than Raymond (the folk lift co.) battery terminal protector. That works about as good as anything. But I have had OK success with the grease and paint as well.
Yonuh, ride over and I will give you a spray!
North Carolina is a bit far for me at the moment.