Windex on ivory keys: Did it remove the gray spots?

There was definitely an improvement after Mark scrubbed the whites and even the black key OFFENDERS with Windex. I don't believe, however, that the gray will ever be totally removed because it had become ingrained into the keys by its introduction through supposedly "shoe-dyed" ebonies. (See https://arioso7.wordpress.com/2012/03/13/piano-maintenance-teaser-graying-ivories-and-a-squeaky-note/) Here are photos that I took 24-hours post…