My galley ice box drains to a T connector with a ball valve isolation on the suction side of the bilge hand pump in the lazarette. The hose that goes to the bilge from that T also has a ball valve. This way I can isolate the suction to the ice box only and can pump it empty. I thought this was OEM as well as it is a professional install. This will not get all of the water out of the drain line though. If Im only leaving the boat for a week, I don't bother draining the hose, but any longer and I use a brass oil transfer pump to remove it.
Chris
Chris