Once you break through the glaze. Spray bottle of water does the trick.. trying to get through the glaze is when you break it.Correct tile bit and drilling a hole in tile is easy.
Google how to drill a hole in tile and see it done.
I bought a diamond hole cutter for tile to run the pipes out of the wall when installing a shower head etc.
Yea it was like $36 15 years ago but a great purchase when you need it.