It was easy. I finally got some vinegar and filled it up and let the kettle sit overnight. Rinsed it and gave it a wipe with a wad of paper towel and the scale and residue from the scale is all gone.
Shoulda done it earlier. The wasted psychic energy, every time I peered in and saw the scale…
I keep a box of citric acid crystals around for this and the coffee pot/espresso machine. It descales as well as vinegar (for the kettle I just put a few scoops in and boil with water) and there’s no aftertaste/smell like there is with vinegar.
I use lemon juice in the coffee machine every 6 mo or so for samesies.