Contralube is a fantastic synthetic gel that has been designed to protect electrical contacts and connections. It is suitable for all types of electrical connections from small signal RF through to high voltage and current systems. It has a breakdown voltage of 10kV and keeps water (including salt water) away from contacts.
You apply Contralube liberally to the contact area and the gel will creep away from all the microscopic pressure (contact) points but leave the points surrounded by gel to protect them from the elements.
I’ve been using Contralube 770 for about 4 years now and can confirm that the level of protection provided is excellent. It also works exceptionally well as an antenna protector and I apply the gel to all the contact areas of the antenna. By keeping air and moisture out, corrosion is significantly delayed or in many cases prevented altogether.
All the major suppliers carry Contralube, i.e. Amazon, Maplin, Farnell, RS Components.