Adding fresh water wash down

Good afternoon
I am planning on adding freshwater wash down to my anchor locker. My approach would be to tap into the cold water supply of the galley sink by adding a Tee fitting. My question is if anyone has experiencing accomplishing this and advise on how hard it is to route the supply line to the anchor locker thru the port side of the cabin.
Thanks
Rich

Hey Rich

did you get ever get this accomplished?