We had a leftover cylinder of this stuff in a lab where I was a post-doc. I demoed it for grad students for a laugh.
Also fun SF6 fact: it has a global warming potential of 23,900 times that of CO2. Most of it is from leaks in high-voltage switch gear and equipment. I remember a US Department of Energy report where they were able to reduce their greenhouse gas emissions by like 90% over a few years just by eliminating leaks of this "harmless" gas.