I'd shoot their arses but not with a gun. I'd put bullets between the fingers of a clenched fist and punch them in.
It might not be quick but the scum'd certainly have time to reflect on their dissolute existence.
VOTE RAT
When my Aunty Vi was a cleaner, she used to drag the patients out of lungs so she could bleach the insides. Naturally, most were asphyxiated before she put them back in. Still, you could punch a nun them days and still have change from a shilling