Not sure if sam showed on his henry rebuild last week or not, anyway in the past i have used silicone gel, comes in a shoe polish type container.
I have also used it on car electrical contacts, last time was on our lasses astra auto gearbox selector switchingunit, that was 7 months ago with no problems
Trucklite nyk - 77 is probably same sort of thing, use sparingly as it absorbs dust.