A better place to send them could be to our good ol' local Sun: the victim can be frozen solid in the 3-4°K in space, become asphyxiated by the vacuum from space, become radiated to death by the sun's harmful UV rays, and their blood will 'boil' and freeze in space because the pressure in the human body is almost infinite compared to space's because there's no pressure in space! And as the victim approaches the Sun at an alarming rate, they will finally thaw out and be burnt to death². This process is way more faster than what you have mentioned btw and is more effective and efficient.
Sorry for the long paragraph...
