My ceramics had both burned on oil and anti freeze stains. To clean was super easy, safe and quick
If you have a bench grinder, get a polishing fabric wheel and rogue (like you would use to polish stainless or metals) from Harbor frieght, about $20 with the rougue.
I had heavily burned on oil and antifreeze stains off in LESS than 5 seconds. And it turns the ceramic very shiny, with very little effort. QUICK, easy to use.
Use the fine rogue (green) , thats all you need
To clean up after the rogue, just a little hand rub with Mothers
You need high speed to clean off the stains (hence the bench grinder mounted fabric wheel) . For the rest, hard to get areas, use a drill mounted ball to clean the not so bad areas
It takes very little effort to clean with the bench grinder mounted fabric wheel
DO NOT USE STEEL WOOL OR FINE SAND PAPER ON CERAMICS
Now you can polish bolts, aluminum, your stainless trim all on your own