lim, Welcome to the Router Forums!
"Ceramics" is an extremely broad term - it can mean almost anything that has been fired to become hardened. For example: clay bricks are ceramic, technically speaking glass is ceramic, coffee mugs are often ceramic, many forms of tile are ceramic, lots of medical equipment is also ceramic.
Since this is a router forum, I'm going to "stick my neck out" and say to utilize the same practices you have found that work for you on test pieces of glass - then try those on a scrap of the ceramic you're trying to machine. Be cautious when machining ceramics and glass - because the dust is super-fine and dangerous to breathe and abrasive to motor windings. If you have a way to use an air-powered (pneumatic) router or something with a TEFC (Totally Enclosed Fan Cooled) motor you will go a long way toward avoiding the motor dangers, but not the lung dangers.
I have owned a ceramic business in years past and still, on occasion; have need for ceramic parts in my prototype business. In my opinion, ceramic sleeve bearings are second-to-none for the situations where we have employed them.
I hope this helps!
Otis Guillebeau from Auburn, Georgia
OPG3 Tweak everything!