I have made similar thing with clasic EURO connector (computer power cable extension )
3ft Computer 18 AWG Power Cord Extension (IEC320C14 to IEC320C13) .... they are litle bulky but bullet proof and aveable anywhere and cheap.
Point is that are
moulded completly in plastic , special part where is joint between Cu cable and brass socket ( can create galvanic series ) and water could not leak through wires .
( have cut one on metalurgical saw to be completly sure )
Plug and socket are designed for high current , high voltages and both have suitable dimensions.
Q:What is point of E/O cord ? A: That the appropriate distance between the two conductive pins (insulating path) and that electric can not establish electrical circuit (leaking current )
I have made thin seal and put it on a male plug . When connected electrical path is isolated and water is and the water is squeezed out of the connector because of its shape. ( without cavities in the
connector ) . But for safety it must be connector marked for use only with low voltages.
Besides euro connector gives a wide specter of connectors ( straight orientated , angled ) for server racks is also extension combination completly moulded in plastic with male input on one branch and two
separated branches with female output (UPS to disk array/server ) could be used for video lights splitter ....