I doubt that it is any chemical solution because that would make a dangerous amount of vapor. Although there probably is certain chemicals that might work for something like that, what he is using is most likely water
Yes, molten bismuth will definitely burn. Something I found out recently is bismuth salts might have a much longer half life than traditionally believed. I have read a lot of convincing website articles about new research suggesting that bismuth salts can be detected weeks if not months after...