for plastic/epoxy packaged parts, this stuff will dissolve the package. Lightly applied, it will remove the surface including any markings.

Since you're dealing with ceramic parts, mild abrasives applied in a relatively conductive environment (the entire board sitting on a conductive mat, perhaps?) and worked with an erasing machine with the eraser dipped in pumice might just do the trick. The key will be to conceal that you've done it, else they'll take up the implied challenge.

RE