Years ago when we lived in Colorado, we’d wash our cast iron skillets like this:
After supper has been eaten and the campfire is dying down, tie your rope into the hole in the end of the pan handle, throw the pan into the creek, and tie the other end of the rope to a willow bush.
Next morning, after catching and cleaning a few trout for breakfast, pull the clean pan back to shore with your rope, untie and stow the rope, and get ready to make breakfast.
CD in Oklahoma