No matter. fast-on terminals, clamp battery posts, lugs, whatever, silicone dielectric grease will only prevent contact if a connection is laid atop another with gravity holding it there. I am not arguing the dielectric integrity of the substance, merely dispelling the notion that if it is applied, conductivity will be lost in automotive electrical applications.
Terminal washers are excellent if if if if they are properly saturated with oil or preservative. NoCo terminal washers are good. DEKA brand washers are almost useless right out of the can. Saturate almost dry DEKA felt washers will oil or silicone grease and they will then work fine. When I run out of washers, a thick smear of silicone grease around the battery post to case, seal circumference works just as good.
