I think there should be a simple tutorial on training slaves, simple because certain slaves are extremely difficult while others are easy.
There'll be a simple system ready for this in the 0.7.7 (january) update, as it's connected to the new inventory system that goes live on test servers today.
0.7.6 features a much more stream lined way of equipping slaves and applying states to them, but I need to test it first before moving forward.
I've made it so the dildo stool produces anal xp for inexperienced slaves, however, and it's added to the 0.7.6 update already. As a temporary fix to the Massive C**k trait and slaves with low anal proficiency.