I thought I ask before I try this. I watch the youtube video on it. Shows him using a slave that can use a hammer animation. The slave does hammer animation when mining. Do I need slave that can use hammers for them to be able to mine in a private mine. I know they have to a hammer on them. But can ghoul slave mine or just only slaves with hammer animations?
Just in case you weren't clear from the previous reply, you don't have to put slaves in a mine that have a hammer animation. So, in summary, they don't need a hammer in their inventory and they don't need hammer animations either. I have used a variety of slaves and never had an issue with this.
There are some other issues with slave mining, however.