Wanted some thoughts here. I maintain a fleet of Hyster forklifts running Mitsubishi 4cyl engines. We had run into issues after pressure washing them with moisture in the spark plug cavities causing a misfire. I had been using Silglyde on them and it would be almost crusty when I pulled the coils. Switched over to a blue synthetic caliper grease and the problem has largely disappeared. Any long term issues using caliper grease on these? I figured it's gotta be safe for rubber and can take the heat.