I've done it, Luke's done it, he is actually coming in and out of the doggie door unassisted. He actually used his own little brain yesterday and came in without any coaxing; he was some proud of himself. I have to admit I am some proud of him; not that I didn't think he could use it, I just never thought that he would. I knew he could do it; he just didn't know it.
Luke's learning process is a little different than the norm; that said there are no two dogs alike. There may be similarities in how dogs learn but no two are identical; so sometimes you need to put on your thinking cap. We had several obstacles to get over with Luke.
First he had to get over his touch issue which is the reason I thought the door would not be on his "things to do" list. The touch issue took the bulk of the time, convincing, coaxing and generally making a fool out of myself. Once he was over that hump we had the push issue, another biggy. So by working backwards to my goal the open spot on the flap became smaller and smaller; there was no choice if he wanted in.
Once he got the whole pushing thing down, it was time to shut up and let him learn. This "shut-up" stage is very important; the dog must figure it out on their own or they will never do it on their own. There comes a point when you know that they know and you just have to wait.
That point was yesterday for us, I told everyone not to say anything and ignore Luke peering in the window. It only took 1/2 a minute and low and behold there he was upstairs in my room. Spinning and huffing like a mad fool; he had figured it out. He may have an occasional brain freeze where he stands looking at me on one side of the door realizing that he is on the other side. But with patience and keeping quiet, he'll figure it out once again.
The most impactful lessons are those when your dog figures it out on their own. This lesson is stored away for use down the road unhindered by commands, signals and unnecessary blabbing from us.