WD40 is not a lubricant, it's a water repelant.
I would use white grease.
Without wanting to engage you in any technical debate, I would like to say that your assessment is only partially correct. Repelling water is just one function of the product.
Its primary function is actually a penetrant which is why it is so widely used world-wide by mechanics to free seized devices.
It also improves conductivity due to its graphite content.
Unfortunately, because it needs to be thin to penetrate, its effect does not last for a long time which is why I said that the application in question needs a thicker lubricant.
I note that you recommended white grease; in fact, graphite grease (black) would last longer and it resists water better than other grease.
Nowadays, we have white, bronze, grey, brown, black and whatever other types of grease... but they generally do the same job. Some do look better than others though.
Thank you for your input.