Dear Smirch,
I am no Pro, but I have struggled with the ugliest push slice this whole season. I am now at a point where I think I have it behind me. I can only offer some of the things I have tried and things I have found out in the hopes that it may be of some value to you.
It started in the beginning of the season, and was spontaneous. It might last one hole or 15 holes. It destroys your confidence and makes your knees tremble everytime you step up to the tee, wondering "Is it coming this shot or not". Believe me, I know what you are going through. It was always with the
irons, woods were fine.
I went to three pro's for a lesson and was never offered a root cause. Some of the causes offered were: swaying in the hips, Blocking the wrists, moving the upper body toward the target, etc.
I finally started turning things around by going to the park near me and hitting balls with only 1/2 swing with 9 iron. At first I was even push slicing them too. I stopped all hip movement and only swung with the arms. Bingo, the ball started going straight. Pretty soon, I was able to hit the ball every time straight with this abbreviated swing. I kept at it but still had problems on the course. Then I tried standing a little farther away from the ball, suddenly I was hitting the ball just fine. In fact, try hitting the ball off the toe of the club. See if it helps. I had also seen lots and lots of improvement by using Greg Willis's "Right Hand drill". It is an amazing drill and really helps.
In the final analysis, and after mulling all this info over, I think I had started to move the ball too close to my body and didn't notice it. Then, unconsciously, I was trying to correct for it and started casting the club which doesn't allow me to get the clubface closed by the time it comes into the impact zone. During a push slice, the club comes in on an in-out swing path with the clubface hitting the ball way open.
Your situation my be totally different, but I offer my experience only as a starting point.
Good Luck, Let me know how you are doing...
Chessbum....