Yes they work on artifacts and enhanced items. You still need to be in non-combat mode and then double click on them. You need to be near them in order to get the cursor to dye your item and if they move too far before you dye it, it won't let you dye the item. Haved fun chasing them. I did find they stayed still a bit longer when my dragon was attacking them. You can't command the dragon to attack, but if it is guarding you and you get attacked by the slime, then the dragon will start attacking and chasing it. When it stops to fight the dragon I find I have better luck clicking on it and dyeing my stuff.