Several years ago, I was using some Watco, I threw the rags into a tall garbage can. They had been in there about 30 minutes when I went into wash my hands before starting on another project, when I walked in the door it had just burst into flames. Nothing was hurt but I certainly got a valuable lesson. I bought a small metal garbage can and sprayed the inside edge of the rim with that silicone sealer they advertise on TV. It couldn’t be tighter and was about $50.00 cheaper and bigger than a dedicated rag bucket. However my FIL was a saftey officer at a prison and he thought I was nuts not to buy the real deal rag bin. I really like this better. After reading this post I feel good a fire fighter uses a similar arrangement.
Mike

Mike