I would worry about anyone washing a cast-iron skillet with water! The other things, not so much.
Here’s some “thread-drift” for ya’:
There is considerable differences of opinion out there on how to care for cast-iron.
The most common is “Never use soap/water” to clean it….because it “ruins the seasoning” .
This is an old wives tale….the background of which is rooted in the 18th/19th century …when women and travelers did not have ready-access to water.
Imagine traveling by wagon or cart or foot on the Westward-movement. Water was a prime concern. Stops were hopefully found at stream-crossing where water was available.
Otherwise, the cast-iron pots were scraped-out of food-particles, and cooking-grease or lard was used to prevent rust. This becomes a non-stick coating that became known as “seasoning”.
It wasn’t specifically planned-for as a non-stick surface….That was simply a side-benefit. The reason the pot wasn’t washed was: Water was precious, especially when traveling. (The two barrels on the side of the wagon was water for the harness-animals and people…. and the other was corn or feedstock for them.
Using water for washing was simply not prudent Or possible.… and the concept of “germs” was completely unknown. The act of cooking in that cast iron post had a fortuitous side-benefit as regards germs…. and “soap” was usually “lye”…used primarily for clothing, etc when a stream/river was available.
Modernity has changed all that. But habits and “old sayings” die hard.
”Seasoning” a new skillet is a universal ritual, mostly due to tradition and unfamiliarity with the real reason it was ever the practice. Using a quality fat or oil to “season” new cast-ironware is good.
But there’s simply no good reason to worry about “ruining” cast iron with proper washing using dish detergent and water. (Simply scraping food particles out with a spatula and leaving the pot with grease in it is NOT necessary OR Good for you…. it allows minute food particles to spoil and feed germs… and the ritual lard or animal fat used to prevent rusting will spoil and become Rancid… ruining the taste of newly-cooked food and contributing to the possibility of food poisoning.
Good modern care:
When finished with cast iron, scrape food away, …then use hot water and dish detergent along with a stainless-steel “scrubby” (pot-scrubber) …to scour and clean the cooking surfaces completely. After many months and years of using that metal pot-scrubber….your cast-iron will slowing acquire a very smooth and “slick” surface.
Rinse with hot water thoroughly, then place the cast iron on a stove-top burner …or inside a hot oven…. to thoroughly Dry the iron.
Next, use a few drops of Olive Oil on the cooking-surfaces and spread it thinly with a paper-towel while the pot is still hot, and store it away. Do not worry about the “seasoning”.
Next time you use it…simply wipe it out with a paper-towel… and Enjoy It!