charlie wrote:

Worst case is you will be buying a new water heater and that "worst
case" could be right now if you keep screwing with that element.
You may not break the metal can but you can crack the glass lining.

they haven't made them with glass linings for a LONG time

My bet is the bottom of that water heater is slugged solid with
scale and you will be buying a new one soon enough. At least do it
on your own schedule.

Huh, saw glass lined in the local place just yesterday.

well, if it's glass lined, then why a: does it need an anode, and b:
what would rust to produce a hole in the casing?

Because the glass lining is not perfect and does not cover every single square
micron of the tank. The area it does cover reduces the erosion of the anode.