I don't lube mine (maybe I should start?), but I do put a cover on it. I use an old bleach bottle with the bottom part cut away. I have a swing away tongue, so after I swing the tongue to one side or the other, I slip the cover over the tongue and plug. Its held in place by a bungee cord from the handle of the bottle around the straight part of the tongue. This also tilts the bottle slightly down so water (e.g., rain) doesn't accumulate.