I would try the NO-OX-ID A Special. I bought this electrical no oxidation conductive grease two months ago after watching some YouTube Videos on it's application for Model RR track cleaning and maintenance. Wish I had found this stuff years ago. Heck it's been around for 60+ years and apparently was recommended by Lynn Wescott decades ago.
I am using it on the blackened center rail of my gargraves and Ross track and switches as well as all carbon pick up rollers and it has made a big difference.
Anyway, it's available on AMZN 2 ounces should last me the rest of my life for below $7.00