Ceramics, such as glazed wall tiles, are easy. A tungsten-carbide bit such as the #562 or any of the Silicon-Carbide (SiC) (green) stones (83142---85622) will work.
Glass is another matter. I would use the SiC stones with a lubricant, such as water and olive oil, at low speed, to smooth the edges down.
"For almost every problem,
there is a DREMEL solution"
"When all else fails, read the instructions."