Grey water hose

[D Porter]

We have a 2006 Rockwood 1640 PUP.
The drain for the sink is a roughly 2in diameter threaded pipe that comes out the side of the PUP.
Where can I find an adapter that will allow a garden hose hookup? I've seen several for bayonet style adapters but none that are threaded.
It seems like I'm making this considerably more difficult than it needs to be.

Thanks
Dan

 

[Twisty]

Wastewater adapters - He Ruide's Photos

and you could buy it here
PLUMBING FITTINGS AND ACCESSORIES