Re: Vortex Bowl Hole Problem
Tell the vendor first, let them know you will try to drill it and if it works, problem solved. It you break it, they'll still send you another I bet.
Here is what I would try:
First, it is possible that the hole was there before it was glazed and then plugged when refired. It that is the case, you have a great shot at opening it.
Get a #40 or smaller bit. You can find one at any hobby/model train store. Wrap some duct tape around it so it will be large enough to fit in a Dremel tool (assuming you have one). Once the hole is made take a very small round file and work it till it's cleaned out.