I am thinking of doing this same thing. I realize this thread is a little older and hoping that someone has gone through with it.
My idea: a PVC pipe about 6” or so run at a 45 degree through the wall and about a foot out the other end. (I would prefer stainless but I don’t want to spend that much money on this project). Considering some kind of damper on the outside to prevent winter wind blowing into my kitchen. Also thinking I would either install a “pot filler” type faucet near the inside end of the chute, or put a faucet directly in the chute. This way I can make a habit of running some water down after whatever I dump out. I would like to place the inside door recessed into my countertop, but may have to make it wall mounted due to the angle/ height requirements to make it 45 degrees.
I am thinking this plan would allow me to 100% seal the home walls around the pipe, preventing any issues with the structure, and allow easy cleaning and low mess. I am actually looking to do this for my home as well as my mother’s home.
I am interested to hear any input on my idea and especially anyone who has done anything like this.