That might work. However, it would also have the effect of making the entire screen less bright. OLED burn-in is the opposite of CRT burn-in - pixels that have

That might work. However, it would also have the effect of making the entire screen less bright. OLED burn-in is the opposite of CRT burn-in - pixels that have been used more than others shine less brightly. To compensate for that you'd need to drop the brightness of every pixel down to the worst affected pixels. Perhaps you could attempt to increase the power to 'burnt-in' pixels, but that would presumably only compound the problem and reduce their lifespan.