Not sure that author is that wise. He also wrote:
"Dielectric grease is widely used as a sealant for
spark plugs in gasoline or diesel engines, as well as on the gaskets of multi-pin connectors in the electrical systems of vehicles and boats."
I've yet to see a diesel engine with a spark plug. I have seen an old diesel tractor with a gasoline starter engine that did have a spark plug, though.
In my example, I'm thinking that the dielectric grease I gooped on the connector bridged between the pins and conducted that high voltage. When I cleaned off the face of the connector, that bridge was removed.
But I do use dielectric grease on low voltage connectors. I have used dielectric grease on spark plug BOOTS as a sealant, but never saw the need for it on the actual connection. I don't think it would matter if it conducted the 20,000+V of a typical gas ignition system though, because of the short distance between the connector and the spark plug terminal, even if "fully insulated" by the dielectric.
