Is there way to automatically crop white pixels after photomerge. (NOT panoramic images)

I am having issues with photomerge. I select photomerge and load 5 different exposures. In other words I DO NOT blend the images together. Once I create the new image with 5 layers. I like to apply luminosity masks to the images. Sometimes the photomerged image has a single row of pixels along 1 or more sides. That ONLY becomes an issue when applying masks to images. It affects how one layer mask is applied to a layer of different exposure below. It looks like a dark band along the edge of the image. This band is usually about an inch wide on my screen. So it is noticeable. The work around is to crop in before applying the luminosity masks. DELETE CROPPED PIXELS MUST BE TICKED FOR IT TO WORK. Then the luminosity masks can be applied without any issue.  This is more of an issue when I am processing large amounts of images say for a 360 degree roational panoramic of 17 positions where I might need to spend a good hour going back over the problem images, cropping in and then running the luminoisity masks.

 

I attach 2 images. After photomergeing the 5 different exposures, there was a row of white pixles on the top and right. The 1st shows what it looks like when the luminosity masks are applied without cropping in. If you look at the 2nd image, I cropped in prior to applying the luminity mask. If you compare the 2 images you can see a dark band on the top and right of the 1st image. As I said more an issues with rotational panoramics etc.  

 

Is there a way of cropping out the pixels AUTOMATICALLY as opposed to manually having to do it. It would be quite a time saver. Is there a script that could be be incororated into my workflow that could work?