Ah, apologies. In that case you are correct: expecting you have an onwards MH-operated (or even OW-marketed & OW-operated flight) you are not utilising the lounge as an arrivals lounge, but rather as a departures lounge for your flight in 12hrs.

In fact, you can also utilise the CX lounge if open in that case, though they don’t have showers... maybe on your return to the airport prior to your next flight.