I've been having a go at using alcohol inks on clay recently. I can't say that I have cracked it yet but I'm definitely up for trying it out more as it is a lot of fun. Take a gander at my first few offerings.
Mixed ink colours on blue clay.
Tip: The inks don't stand out well on the blue clay!
The following pic is inks on a translucent clay with alcohol inks mixed in.
Tip: the inks are a little dark on an alcohol ink base!