The easiest way I have found to get candle wax off a metal chanukia is with a stream of hot water. The wax melts and runs off with the water.
One kettle of hot water is not enough to clean it all, and the tap in our kitchen is not high enough above the sink to fit this particular large chanukia under it.
Can I clean the chanukia in a bath or shower, or must it not be taken into the bathroom because of its kedushah?