Charcoal starter makes sense. I don’t use charcoal due to the cost and when I did, I used a chimney. I use wood in the smoker and start that with a chimney as well even though most people start with charcoal and use it to start the wood.
Can’t think of anything I could use this thing for. Maybe warm up water in the ringer washer which is outside where there’s no hot water supply. I usually fill a few one gal plastic jugs to add hot water to the cold.
I would not stick it in the water directly!! I would put it in a metal pal and then a metal bucket of water on top. So the iron piece had contact with the water bucket. I also would not have it on all the time. Probably not designed for continual use and it’s old too. Maybe a timer or just use it when it freezes until the water is thawed. Good luck!