Another Ceramic Sink Taphole question

[DIYinBerks]

I need to fit an overcounter ceramic sink in a few days time.
Looking at the instructions, it says use a centre punch (a pointed tool) but shows a blunt tool in the photo - looks like a 1/4" socket set extension bar.
Any advice here?
I called Howdens but they were not helpful - I am thinking that using my diamond tile router might be a better/safer way to get a neat hole.
Anyone used anything like this?

 

[polesapart]

I've done it. Firm, confident blow required. Centrepunch IIRC.

Satisfying when it works.

Only ever shattered one basin. That was less fun.

 

[DIYinBerks]

Only ever shattered one basin. That was less fun.

I only have one to do or