Returning home after using cast iron cookware on a camping trip, I forgot to clean the cast iron in the midst of much unpacking and other matters. As a result of A) leaving any cookware with food in it for almost a week, and B) leaving a cast iron pot sealed with its cover on it, there was more mold in that cast iron pot than I'd ever seen on any cookware before.
My main priority was to clean all the mold ASAP. I put the pot and pan (lid) outside in my yard, poured bleach on it, then followed up with boiling water. That seemed to kill all the mold, and nearby grass. After that, and rainy weather the following day when I intended to leave it outside to air out and dry in the sun, the cast iron became very rusted.
Now I embark on the task of scraping off all the rust using steel wool, scrubbing the cookware with soap, rinsing it in hot water, drying it, then reseasoning it. This all has me wondering: when cast iron cookware gets very moldy, what's the most efficient and accessible way to make it hygienic and usable again?