This is seriously required, especially when joining/detaching objects, and exporting them for game engines. Can anybody tell me how to deal with the issue of cleaning unused materials on an OBJECT (not clean materials from the scene or orphaned data). The built in 'Material Utils' add-on used to do this but does not exist in 2.8 (not to mention all the other useful functions of this material!).
(the image is from 2.79)