So... this isn't exactly the same thing, but I spend about 1/3 of my development time "cleaning" images. Cutting out text, changing backgrounds to #222 instead of white, and drawing polygons around girl's hair and eyes so I can use GIMP's Colorize tool on them.
I'm not interested in teaching, but it's basically the same skills used by manga cleaners, and I was wondering if anyone here has that skillset and would like to help out. :) If you're not already a supporter, I'd be happy to make you one.
If you're interested, contact me using the site form, or comment here.