Was a Combat Engineer in a previous life, can tell you that lighting magnesium isn’t easy unless it’s in the form of shavings or powder in which case it’s almost like gunpowder. Never tried to put it out once we got it lit but we were told to try and cut off the oxygen source with mud if we needed to put it out. Once it’s going it’s scary stuff.
When I was in science class in my teens I bought some magnesium strips (I was into model rockets) you can light that stuff up, drop it in a glass of water, Brother, it keeps cooking Man!