For years I've used waxoil & wd40 mixed to something the consistency of cold engine oil & use that on all electrical connectors, applied with a small paint brush.
Runny enough to get everywhere (literally) & thick enoigh to stay there.
Currently 80k year round on a Transalp which sometimes lives outside & all connectors are perfect but gets used on all my bikes when meddling.
Wd40 & such like offer little lasting protection, with grease, it's difficult to cover all of the terminals & bare wire.
I guess anything is better than nothing.
P