Burn-in is a result of physical changes to an OLED cell. If these changes are temporary, some sort of "relaxation" period may reduce the visual artifacts.

I'm sorry, I lost the link to the synopsis of a research paper indicating that the v-i curve changes for burned-in pixels. This suggests a technique for dealing with pixel drift over time. One could map the v-i characteristics of each pixel (perhaps during a power cycle or maintenance run), then store a dot-by-dot correction factor in a table lookup applied to each displayed frame.