I’m currently using Blender 2.8 and the function to remove unassigned materials from a mesh doesn’t seem to be available anywhere. In 2.79 there were 2 addon’s that dealt with this, “Material Utils Specials” and “Amaranth”. They both had options for cleaning out material slots on an object. What is the workflow in 2.8 for doing this?
Amaranth has been removed from 2.8 RC2. I have noticed this in Windows, Linux and OS X versions and dont know why.
But I downloaded latest version and installed in my Blender 2.8.
It seems to work and may solve your problem.
Hope this help.
when you mean the latest version do you mean from the Amaranth website or from github? I couldn’t find my way around github at all and couldn’t find any other downloads for it, but i did see a thread that someone was updating it.
Sorry for my mistake with the solution. I have been trying to recreate it and havent been able to install and make it work in 2.8
BUT
If you download the latest nightly of 2.8 Amaranth toolset is there again.
oh man you are a life saver… I’ve been so busy I never even thought to see if there was a fix in the official Blender builds. Really appreciate it, you’ve been a massive help. 
seems they have removed it from the official release candidate however…
It has been removed too from final 2.8 stable. Dont know why.
Community addons are by definition not stable. Hence, they don’t get into the stable Blender releases.
Buh?!?!? Isn’t that a bit elitist? Just because a community member made it doesn’t mean it can’t possibly be stable. Or am I misunderstanding something?
It has nothing to do with elitism. All addons, stable and community are in the end created from someone in the community. It’s simply that the “community” addons (it’s just a name) don’t quite meet the pretty stringent code standards, or aren’t actively maintained by their authors, or are very niche, or their authors simply don’t consider them finished. When an addon is added to the stable release, the BI takes upon itself the burden of keeping it maintained, even if their author quits, for the foreseeable future, or until they become redundant. So it’s not a trivial concern. Community addons on the other hand are subject to change or removal at any time.