Albino Chipmunk
Tiller
As of versions 1.6 and above pre-1.6 clay farming has been patched unless legacy clay farming has been enabled for a save file.
In 1.6 there's a new item called treasure totem, and it spawns a ring of artifact spots around the player. The treasure totem recipe is unlocked by unlocking the foraging mastery and is made using 10 moss, 5 hardwood and 1 mystic sap. Treasure totems can be used on any tillable tile even the ones in the mines. Since the artifact spots in mines don't have a drop table on their own, you can use treasure totems to farm clay this way.
I'm not sure if the generous enchant on a hoe affects artifact spots.
In 1.6 there's a new item called treasure totem, and it spawns a ring of artifact spots around the player. The treasure totem recipe is unlocked by unlocking the foraging mastery and is made using 10 moss, 5 hardwood and 1 mystic sap. Treasure totems can be used on any tillable tile even the ones in the mines. Since the artifact spots in mines don't have a drop table on their own, you can use treasure totems to farm clay this way.
I'm not sure if the generous enchant on a hoe affects artifact spots.