I've been working on mastering the 4*4*4 Rubik's cube, and have hit a road block, namely OLL parity. In this case, 2 edge pieces are flipped in their correct position, and the rest is solved. PLL parity, where edge pieces are swapped, can be solved intuitively. There is an algorithm to solve OLL parity, but it is long and involved and I don't want to memorize it. I'm looking for an intuitive way to fix it, even if it takes longer.