You have that statement a bit wrong.
A plugged cat can be 100% ruined by drilling holes in it is what you actually mean.
Drilling holes in it doesn't solve the fact that it was plugged up.
What you should be asking is:
What plugged up the catalytic converter?
Has the cause of the converter being plugged up been resolved before you replace it?
Drilling a converter solves nothing, and will only cause the car to fail an emissions test, if it needs to pass one in order to be registered in the state.