After a much needed break from my project, I have come back afresh, ready to try and re-tackle this problem. I have noticed that if I drop the brick that is above the layer(s) being cleared on the very left, then it clears it differently than the others... hopefully you will understand what I mean by the pictures... I was thinking of doing something where I create a new array for storing all of the values except for those of lines that need to be cleared, then moving the lines down after the fact. Does that sound like it would work?
left before, left after, left after-after
not left before, not left after