It became a thing at my elementary school in the 80s to try and sell iron to hobby shops for cash, so kids were tearing out the big magnets from speakers and di

It became a thing at my elementary school in the 80s to try and sell iron to hobby shops for cash, so kids were tearing out the big magnets from speakers and digging into the sandboxes at school to pull iron out of the sand. I never did it because I doubted you could really get money for a few ounces of iron and it looked pretty tedious to dig in a sandbox all day with a fist-sized magnet, and they were ruining speakers to do it. Who knew there was an even more tedious way to do this with clay and water?