You could probably disable scrubbers and start pumping co2 to cause a singulo or tesloose
As stated, stop the gas in the loop and the SM will die. If you want Singlo action then you want to get as much gas as possible in the SM.
Fastest one I saw was an overly enthusiastic CE who pumped my fresh can of HyperNob directly into the SM. Without checking the temperature of the gas first. It was around 1e12 Kelvin or so. This pretty much turned the SM into a super nova within seconds.